Hacker Zhorik wants to decipher two secret messages he intercepted yesterday. Yeah message is a sequence of encrypted blocks, each of them consists of several bytes of information.

Zhorik knows that each of the messages is an archive containing one or more files. Zhorik knows how each of these archives was transferred through the network: if an archive consists of k files of sizes l1, l2, ..., lk bytes, then the i-th file is split to one or more blocks bi, 1, bi, 2, ..., bi, mi (here the total length of the blocks bi, 1 + bi, 2 + ... + bi, mi is equal to the length of the file li), and after that all blocks are transferred through the network, maintaining the order of files in the archive.

Zhorik thinks that the two messages contain the same archive, because their total lengths are equal. However, each file can be split in blocks in different ways in the two messages.

You are given the lengths of blocks in each of the two messages. Help Zhorik to determine what is the maximum number of files could be in the archive, if the Zhorik's assumption is correct.

Input

The first line contains two integers n, m (1 ≤ n, m ≤ 105) — the number of blocks in the first and in the second messages.

The second line contains n integers x1, x2, ..., xn (1 ≤ xi ≤ 106) — the length of the blocks that form the first message.

The third line contains m integers y1, y2, ..., ym (1 ≤ yi ≤ 106) — the length of the blocks that form the second message.

It is guaranteed that x1 + ... + xn = y1 + ... + ym. Also, it is guaranteed that x1 + ... + xn ≤ 106.

Output

Print the maximum number of files the intercepted array could consist of.

Examples

Input

7 6
2 5 3 1 11 4 4
7 8 2 4 1 8


Output

3


Input

3 3
1 10 100
1 100 10


Output

2


Input

1 4
4
1 1 1 1


Output

1

Note

In the first example the maximum number of files in the archive is 3. For example, it is possible that in the archive are three files of sizes 2 + 5 = 7, 15 = 3 + 1 + 11 = 8 + 2 + 4 + 1 and 4 + 4 = 8.

In the second example it is possible that the archive contains two files of sizes 1 and 110 = 10 + 100 = 100 + 10. Note that the order of files is kept while transferring archives through the network, so we can't say that there are three files of sizes 1, 10 and 100.

In the third example the only possibility is that the archive contains a single file of size 4.
		     
		import java.io.*;
		        		    import java.math.*;
		        		    import java.util.*;
	import java.util.regex.Pattern;
	
	import javafx.scene.shape.Line;
		    	     
		        		    public class Main{
		        		  	private static InputStream stream;
		        		    	private static byte[] buf = new byte[1024];
		        		    	private static int curChar;
		        		    	private static int numChars;
		        		    	private static SpaceCharFilter filter;
		        		    	private static PrintWriter pw;
		        		    	private static long count = 0,mod=(long)1e9+7;
		        		    //	private static TreeSet<Integer> ts=new TreeSet[200000];
		public final static int INF = (int) 1E9;
		
		public static void main(String args[]) {
	    	
			InputReader(System.in);
			pw = new PrintWriter(System.out); 
		    new Thread(null ,new Runnable(){
		       public void run(){
		           try{
		        		
		               test();
	
		               pw.close();
		           } catch(Exception e){
		               e.printStackTrace();
		           }
		       }
		   },"1",1<<26).start();
		   	   }
		    static StringBuilder sb;
		    public static void test() throws IOException{
		    	 sb=new StringBuilder();
		    	
		    	 int t=1;
		    	 
		    	 while(t-->0){
		    		
		    		solve();
		    		//pw.println();
		    		//sb.append("\n");
		    	}
		    	//pw.println(sb);
		    }
		    
		    public static long pow(long n, long p,long mod) {
				if(p==0)
					return 1;
				if(p==1)
					return n%mod;
				if(p%2==0){
					long temp=pow(n, p/2,mod);
				return (temp*temp)%mod;
				}else{
					 	long temp=pow(n,p/2,mod);
					 	temp=(temp*temp)%mod;
					 	return(temp*n)%mod;
					 	
				}
			}
		    public static long pow(long n, long p) {
				if(p==0)
					return 1;
				if(p==1)
					return n;
				if(p%2==0){
					long temp=pow(n, p/2);
				return (temp*temp);
				}else{
					 	long temp=pow(n,p/2);
					 	temp=(temp*temp);
					 	return(temp*n);
					 	
				}
			}
		    public static void Merge(long a[],int p,int r){
		        if(p<r){
		            int q = (p+r)/2;
		            Merge(a,p,q);
		            Merge(a,q+1,r);
		            Merge_Array(a,p,q,r);
		        }
		    }
		    public static void Merge_Array(long a[],int p,int q,int r){
		       long b[] = new long[q-p+1];
		        long c[] = new long[r-q];
		        for(int i=0;i<b.length;i++)
		            b[i] = a[p+i];
		        for(int i=0;i<c.length;i++)
		            c[i] = a[q+i+1];
		        int i = 0,j = 0;
		        for(int k=p;k<=r;k++){
		            if(i==b.length){
		                a[k] = c[j];
		                j++;
		            }
		            else if(j==c.length){
		                a[k] = b[i];
		                i++;
		            }
		            else if(b[i]<c[j]){
		                a[k] = b[i];
		                i++;
		            }
		            else{
		                a[k] = c[j];
		                j++;
		            }
		        }
		    }
		    
		  
			public static long gcd(long x, long y) {
				if (x == 0)
					return y;
				else
					return gcd( y % x,x);
			}	
			
			public static boolean isPrime(int n) {
				if (n <= 1)
					return false;
				if (n <= 3)
					return true;
		 
				if (n % 2 == 0 || n % 3 == 0)
					return false;
		 
				for (int i = 5; i * i <= n; i = i + 6)
					if (n % i == 0 || n % (i + 2) == 0)
						return false;
		 
				return true;
			}
			
		        static LinkedList<Integer> adj[],adj2[];
		        static boolean Visited[];
		        static HashSet<Integer> exc;
		        static long oddsum[]=new long[1000001];
		        static long co=0;
		        static int indeg[],outdeg[];
  		      
		    
		    	private static void buildgraph(int n){
		    		adj=new LinkedList[n+1];
		    		adj2=new LinkedList[n+1];
		    		Visited=new boolean[n+1];
		    		levl=new int[n+1];
		    		indeg=new int[n+1];
		    		outdeg=new int[n+1];
		    		for(int i=0;i<=n;i++){
		    			adj[i]=new LinkedList<Integer>();
		    			adj2[i]=new LinkedList<Integer>();
		    		}
		
		
		    	}
		      
		       
		        static int[] levl;
		        static int[] eat;
		        static int n,m;
		        static int price[];
		        //ind frog crab
		    
		        
		        static long d,x,y;
				static long modInverse(long A, long M)
				{
				extendedEuclid(A,M);
				return (x%M+M)%M;    //x may be negative
				}
				static void extendedEuclid(long A, long B) {
				if(B == 0) {
				d = A;
				x = 1;
				y = 0;
				}
				else {
				extendedEuclid(B, A%B);
				long temp = x;
				x = y;
				y = temp - (A/B)*y;
				}
				}
		        static double distance(int x1,int y1,int x2,int y2){
		        	return Math.sqrt((x1-x2)*(x1-x2) + (y1-y2)*(y1-y2));
		        }
		        static double area(int x1, int y1, int x2, int y2, int x3, int y3)
		        {
		           return Math.abs((x1*(y2-y3) + x2*(y3-y1)+ x3*(y1-y2))/2.0);
		        }
		        static boolean isInside(int x1, int y1, int x2, int y2, int x3, int y3, int x, int y)
		        {   
		           double A = area (x1, y1, x2, y2, x3, y3);
		         
		           double A1 = area (x, y, x2, y2, x3, y3);
		         
		           double A2 = area (x1, y1, x, y, x3, y3);
		         
		           double A3 = area (x1, y1, x2, y2, x, y);
		           
		          return (A == A1 + A2 + A3);
		        }
		      
				static int col[];
		    public static boolean isVowel(char c){
		    	if(c=='a' || c=='e'||c=='i' || c=='o' || c=='u')
		    		return true;
		    	return false;
		    }
		static long arr[], lazy[],ans[];
		static int c[],nodes[];
		static int dp[][];
		static long a[][];
		
		private static boolean isPrim(long n,int p){
			for (long i = 2; i * i <= n; i++) {
		        if (n % i == 0 && i <= p) return false;
		    }
		    return true;
		}
		//price - starting index of string with given hash
		//rating-count of number of time of a hash
		static ArrayList<String> all_perm;
		static boolean[][] visited1;
		static  boolean won;
		static boolean containsCycle;
		static ArrayList<Integer> anss;
		private static int size = 0;
		public static void solve() throws IOException{
			int n=nextInt();
			int m=nextInt();
			long a[]=nextLongArray(n);
			long b[]=nextLongArray(m);
            HashMap<Long,TreeSet<Integer>> hm=new HashMap();
            long pre[]=new long[m];
            pre[0]=b[0];
            for(int i=1;i<m;i++)
            	pre[i]=b[i]+pre[i-1];
            for(int i=0;i<m;i++)
            {
            	if(!hm.containsKey(pre[i]))
            	{
            		TreeSet<Integer> madar=new TreeSet();
            		madar.add(i);
            		hm.put(pre[i], madar);
            	}
            	else
            	{
            		TreeSet<Integer> madar=hm.get(pre[i]);
            		madar.add(i);
            		hm.put(pre[i],madar);
            	}
            }
            long sum1=0;
            long curr=0;
            int ans=0;
            for(int i=0;i<n;i++)
            {
            	sum1+=a[i];
            	if(hm.containsKey(sum1))
            	{
            		int min=hm.get(sum1).first();
            		TreeSet<Integer> lol=hm.get(sum1);
            		lol.remove(lol.first());
            		curr=pre[min];
            		ans++;
            	}
            }
			pw.println(ans);
		}
		private static int mySoln(int n,int a,int b){
			int tempa=Math.min(a, b);
			int tempb=Math.max(a, b);
			ArrayList<Integer> list = new ArrayList<Integer>();
			for(int i=1;i<=n;i++){
				list.add(i);
			}
			
			int round=1;
			while(true){
				ArrayList<Integer> temp = new ArrayList<Integer>();
				
				for(int i=0;i<list.size();i+=2){
					if(list.get(i)==tempa && list.get(i+1)==tempb){
						
						return round;
					}
					if(list.get(i)==tempa ||  list.get(i)==tempb){
						temp.add(list.get(i));
					}else if(list.get(i+1)==tempa || list.get(i+1)==tempb){
						temp.add(list.get(i+1));
					}else{
						temp.add(list.get(i));
					}
				}
				
				list.clear();
				for(int i:temp){
					list.add(i);
				}
			
				round++;
			
				
			}
		}
		private static int othersoln(int n,int a,int b){
		for(int i=16;i>=0;i--){
			if(BB(a,i) ^ BB(b,i)){
				int m=i+1;
				
					return m;
							
		}
		}
		return 0;
		
		}
		private static boolean BB(int n,int i){
			return (n & (1<<i)) >0;
		}
				private static boolean check(int x,int y,int n,int m){
			if(x>=0 && x<n && y>=0 && y<m)
				return true;
			return false;
		}
				
				
				
				private static void dfs(int curr,int par){
			Visited[curr]=true;
			for(int i:adj[curr]){
				if(!Visited[i]){
					dfs(i,curr);
				}
			}
			dp[curr][nodes[curr]]++;
			for(int i=0;i<26;i++){
				dp[par][i]+=dp[curr][i];
			}
		}
	
		
		
		    private static boolean Check(int x,int y,int n){
				if(x>=0 && x<n && y>=0 && y<n)
					return true;
				return false;
			}
		    
		    public static String reverseString(String s) {
				StringBuilder sb = new StringBuilder(s);
				sb.reverse();
				return (sb.toString());
			}
		    
		  /*  
		   private static void BFS(int sou){
		    	Queue<Integer> q=new LinkedList<Integer>();
		    	q.add(sou);
		    	Visited[sou]=true;
		    	levl[sou]=0;
		    	while(!q.isEmpty()){
		    		int top=q.poll();
		    		
		    		for(int i:adj[top]){
		    			//pw.println(i+" "+top);
					if(!Visited[i])
					{
						
						q.add(i);
						levl[i]=levl[top]+1;
					}
					
					Visited[i]=true;
					
					}
				}
			}*/
			
		
		
		
		    		      
		    		   /* private static void kahn(int n){
		    		    	
		    		    	PriorityQueue<Integer> q=new PriorityQueue<Integer>();
		    				for(int i=1;i<=n;i++){
		    					if(indeg[i]==0){
		    						q.add(i);
		    					}
		    				}
		    				while(!q.isEmpty()){
		    					int top=q.poll();
		    					st.push(top);
		    					for(Node i:adj[top]){
		    						indeg[i.to]--;
		    						if(indeg[i.to]==0){
		    							q.add(i.to);
		    						}
		    					}
		    				}
		    		    }
		    		        
		    		        static int state=1;
		    		        static long no_exc=0,no_vert=0;
		    		      static Stack<Integer> st;
		    		      static HashSet<Integer> inset;
		    		     /*   private static void topo(int curr){
		    		        	
		    		        	Visited[curr]=true;
		    		        	inset.add(curr);
		    		        	for(int x:adj[curr]){
		    		        		if(adj[x].contains(curr) || inset.contains(x)){
		    		        			state=0;
		    		        			return;
		    		        		}
		    		        		if(state==0)
		    		        			return;
		    		        		
		    		        	}
		    		        	st.push(curr);
		    		        	
		    		        	inset.remove(curr);
		    		        }*/
		    		        static HashSet<Integer> hs;
		    		       
		    		     
		    		     	static boolean prime[];
							static int spf[];
							public static void sieve(int n){
								prime=new boolean[n+1];
								spf=new int[n+1];
								
								Arrays.fill(spf, 1);
								Arrays.fill(prime, true);
							prime[1]=false;
								spf[2]=2;
								
							for(int i=4;i<=n;i+=2){
								spf[i]=2;
							}
							for(int i=3;i<=n;i+=2){
								if(prime[i]){
									spf[i]=i;
									for(int j=2*i;j<=n;j+=i){
										
										prime[j]=false;
									if(spf[j]==1){
										spf[j]=i;
									}
									}
								}
							}
							
								
							}
		    		     	
		    		    	// To Get Input
		// Some Buffer Methods
		 
		    		     	public static void sort(long a[]){
		    		     		Merge(a, 0, a.length-1);
		    		     	}
		    		    	public static void InputReader(InputStream stream1) {
		    		    		stream = stream1;
		    		    	}
		 
		    		    	private static boolean isWhitespace(int c) {
		    		    		return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
		    		    	}
		 
		    		    	private static boolean isEndOfLine(int c) {
		    		    		return c == '\n' || c == '\r' || c == -1;
		    		    	}
		 
		    		    	private static int read() {
		    		    		if (numChars == -1)
		    		    			throw new InputMismatchException();
		    		    		if (curChar >= numChars) {
		    		    			curChar = 0;
		    		    			try {
		    		    				numChars = stream.read(buf);
		    		    			} catch (IOException e) {
		    		    				throw new InputMismatchException();
		    		    			}
		    		    			if (numChars <= 0)
		    		    				return -1;
		    		    		}
		    		    		return buf[curChar++];
		    		    	}
		 
		    		    	private static int nextInt() {
		    		    		int c = read();
		    		    		while (isSpaceChar(c))
		    		    			c = read();
		    		    		int sgn = 1;
		    		    		if (c == '-') {
				sgn = -1;
				c = read();
			}
			int res = 0;
			do {
				if (c < '0' || c > '9')
					throw new InputMismatchException();
				res *= 10;
				res += c - '0';
		    		    			c = read();
		    		    		} while (!isSpaceChar(c));
		    		    		return res * sgn;
		    		    	}
		 
		    		    	private static long nextLong() {
		    		    		int c = read();
		    		    		while (isSpaceChar(c))
		    		    			c = read();
		    		    		int sgn = 1;
		    		    		if (c == '-') {
				sgn = -1;
				c = read();
			}
			long res = 0;
			do {
				if (c < '0' || c > '9')
					throw new InputMismatchException();
				res *= 10;
				res += c - '0';
		    		    			c = read();
		    		    		} while (!isSpaceChar(c));
		    		    		return res * sgn;
		    		    	}
		 
		    		    	private static String nextToken() {
		    		    		int c = read();
		    		    		while (isSpaceChar(c))
		    		    			c = read();
		    		    		StringBuilder res = new StringBuilder();
		    		    		do {
		    		    			res.appendCodePoint(c);
		    		    			c = read();
		    		    		} while (!isSpaceChar(c));
		    		    		return res.toString();
		    		    	}
		 
		    		    	private static String nextLine() {
		    		    		int c = read();
		    		    		while (isSpaceChar(c))
		    		    			c = read();
		    		    		StringBuilder res = new StringBuilder();
		    		    		do {
		    		    			res.appendCodePoint(c);
		    		    			c = read();
		    		    		} while (!isEndOfLine(c));
		    		    		return res.toString();
		    		    	}
		 
		    		    	private static int[] nextIntArray(int n) {
		    		    		int[] arr = new int[n];
		    		    		for (int i = 0; i < n; i++) {
		    		    			arr[i] = nextInt();
		    		    		}
		    		    		return arr;
		    		    	}
		 
		    		    	private static long[][] next2dArray(int n, int m) {
		    		    		long[][] arr = new long[n][m];
		    		    		for (int i = 0; i < n; i++) {
		    		    			for (int j = 0; j < m; j++) {
		    		    				arr[i][j] = nextLong();
		    		    			}
		    		    		}
		    		    		return arr;
		    		    	}
		    		    	private static char[][] nextCharArray(int n,int m){
		    		    		char [][]c=new char[n][m];
		    		    		for(int i=0;i<n;i++){
		    		    			String s=nextLine();
		    		    			for(int j=0;j<s.length();j++){
		    		    				c[i][j]=s.charAt(j);
		    		    			}
		    		    		}
		    		    		return c;
		    		    	}
		 
		    		    	private static long[] nextLongArray(int n) {
		    		    		long[] arr = new long[n];
		    		    		for (int i = 0; i < n; i++) {
		    		    			arr[i] = nextLong();
		    		    		}
		    		    		return arr;
		    		    	}
		 
		    		    	private static void pArray(int[] arr) {
		    		    		for (int i = 0; i < arr.length; i++) {
		    		    			pw.print(arr[i] + " ");
		    		    		}
		    		    		pw.println();
		    		    		return;
		    		    	}
		 
		    		    	private static void pArray(long[] arr) {
		    		    		for (int i = 0; i < arr.length; i++) {
		    		    			pw.print(arr[i] + " ");
		    		    		}
		    		    		pw.println();
		    		    		return;
		    		    	}
		 
		    		    	private static void pArray(boolean[] arr) {
		    		    		for (int i = 0; i < arr.length; i++) {
		    		    			pw.print(arr[i] + " ");
		    		    		}
		    		    		pw.println();
		    		    		return;
		    		    	}
		 
		    		    	private static boolean isSpaceChar(int c) {
		    		    		if (filter != null)
		    		    			return filter.isSpaceChar(c);
		    		    		return isWhitespace(c);
		    		    	}
		 
		    		    	private interface SpaceCharFilter {
		    		    		public boolean isSpaceChar(int ch);
		    		    	}
		    		    	
		
		}
		    		    
		    		        class Node{
		    		    	int to;
		    		    	long dist;
		    		    	Node(int to,long dist){
		    		    		this.to=to;
		    		    		this.dist=dist;
		    		    	}
		    		    	
		    		    }
		    		        class Qu{
		    		    		long a0,a1,a2,a3;
		    		    		public Qu(long a0,long a1,long a2,long a3) {
		    		    			this.a0=a0;
		    		    			this.a1=a1;
		    		    			this.a2=a2;
		    		    			this.a3=a3;
		    		    		}
		    		    }
		    		
		class Dsu{
		private int rank[], parent[] ,n;
		long str[],si[],larg[];
		long max=0;
		int cnt=0;
		private static int[] parent1;
		Dsu(int size){
			this.n=size+1;
			rank=new int[n];
			cnt=n-1;
			//parent=new int[n];
		    		    		    		parent=new int[n];
		    		    		    		str=new long[n];
		    		    		    		si=new long[n];
		    		    		
		    		    		    		larg=new long[n];
		    		    		    		makeSet();
		    		    		
		    		    		    	}
		    		    		    	
		    		    		    	void makeSet(){
		    		    		    		for(int i=0;i<n;i++){
		    		    		    			parent[i]=i;
		    		    		    			si[i]=1;
		    		    		    		}
		    		    		    	}
		    		    		    	
		    		    		    	int find(int x){
		    		    		    		if(parent[x]!=x){
		    		    		    			
		    		    		    			parent[x]=find(parent[x]);
		    		    		    		}
		    		    		    		return parent[x];
		    		    		    	}
		    		    		    	
		    		    		    	void join(int ind,long val){
		    		    		    		if(str[ind]==0){
		    		    		    			str[ind]=val;
		    		    		    			larg[ind]=val;
		    		    		    			max=Math.max(max, str[ind]);
		    		    		    		}
		    		    		    		int prev_ind=(ind-1);
		    		    		    		int next_ind=(ind+1);
		    		    		    		if(prev_ind>0 && larg[prev_ind]!=0){
		    		    		    			union(prev_ind,ind);
		    		    		    		}
		    		    		    		if(next_ind<n && larg[next_ind]!=0){
		    		    		    			union(next_ind,ind);
		    		    		    		}
		    		    		    		
		    		    		    	}
		    		    		    
		    		    		    	
		    		    		    	boolean union(int x,int y){
		    		    		    		int xRoot=find(x);
		    		    		    		int yRoot=find(y);
		    		    		    
		    		    		    	
		    		    		    		if(xRoot==yRoot)
		    		    		    			return false;
		    		    		    		if(rank[xRoot]<rank[yRoot]){
		    		    		    		parent[xRoot]=yRoot;
		    		    		    		
		    		    		    		larg[yRoot]=Math.max(larg[xRoot], larg[yRoot]);
		    		    		    		
		    		    		    		si[yRoot]+=si[xRoot];
		    		    		    		str[yRoot]=larg[yRoot]*si[yRoot];
		    		    		    			max=Math.max(str[yRoot], max);
		    		    		    		}else if(rank[yRoot]<rank[xRoot]){
		    		    		    			parent[yRoot]=xRoot;
		     
		    		    		    			larg[xRoot]=Math.max(larg[xRoot], larg[yRoot]);
		        		    		    		
		        		    		    		si[xRoot]+=si[yRoot];
		        		    		    		str[xRoot]=larg[xRoot]*si[xRoot];
		    			    		    		max=Math.max(str[xRoot], max);
		    		    		    		}else{
		    		    		    			parent[yRoot]=xRoot;
		    		    		    			rank[xRoot]++;
		     
		    		    		    			larg[xRoot]=Math.max(larg[xRoot], larg[yRoot]);
		        		    		    		
		        		    		    		si[xRoot]+=si[yRoot];
		        		    		    		str[xRoot]=larg[xRoot]*si[xRoot];
		    			    		    		max=Math.max(str[xRoot], max);
		    		    		    		
		    		    		    		}
		    		    		    		cnt--;
		    		    		    		return true;
		    		    		    	}
		    	
		    		    		     
		    		    		    }
	class Pair1 implements Comparable<Pair1>{
			long price,rating;
			Pair1(long a,long b){
				this.price=a;
				this.rating=b;
			}
			@Override
			public int compareTo(Pair1 arg0) {
				
					return (int)(price-arg0.price);
				
			}
		
		
		}
		  
		
