Polycarpus loves lucky numbers. Everybody knows that lucky numbers are positive integers, whose decimal representation (without leading zeroes) contain only the lucky digits x and y. For example, if x = 4, and y = 7, then numbers 47, 744, 4 are lucky.

Let's call a positive integer a undoubtedly lucky, if there are such digits x and y (0 ≤ x, y ≤ 9), that the decimal representation of number a (without leading zeroes) contains only digits x and y.

Polycarpus has integer n. He wants to know how many positive integers that do not exceed n, are undoubtedly lucky. Help him, count this number.

Input

The first line contains a single integer n (1 ≤ n ≤ 109) — Polycarpus's number.

Output

Print a single integer that says, how many positive integers that do not exceed n are undoubtedly lucky.

Examples

Input

10


Output

10


Input

123


Output

113

Note

In the first test sample all numbers that do not exceed 10 are undoubtedly lucky.

In the second sample numbers 102, 103, 104, 105, 106, 107, 108, 109, 120, 123 are not undoubtedly lucky.

	
	    /*
	     * Author- Priyam Vora
	     * BTech 2nd Year DAIICT
	     */
	     
	            
	    import java.io.*;
	    import java.math.*;
	    import java.util.*;
	    import javax.print.attribute.SetOfIntegerSyntax;
	     
	    public class Graph1 {
	    	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=1000000007;
	    	private static TreeSet<Integer>ts[]=new TreeSet[200000];
	    	private static HashSet<Long> hs;
	     
	    	 public static void main(String[] args) {
		        	InputReader(System.in);
		    		pw = new PrintWriter(System.out); 
		            new Thread(null ,new Runnable(){
		               public void run(){
		                   try{
		                       soln();
		                       pw.close();
		                   } catch(Exception e){
		                       e.printStackTrace();
		                   }
		               }
		           },"1",1<<26).start();
		       }
		    
	    
	    	public static long gcd(long x, long y) {
	    		if (x == 0)
	    			return y;
	    		else
	    			return gcd( y % x,x);
	    	}
	    	
	    	private static int BinarySearch(int a[], int low, int high, int target) {
	    		if (low > high)
	    			return -1;
	    		int mid = low + (high - low) / 2;
	    		if (a[mid] == target)
	    			return mid;
	    		if (a[mid] > target)
	    			high = mid - 1;
	    		if (a[mid] < target)
	    			low = mid + 1;
	    		return BinarySearch(a, low, high, target);
	    	}
	    	
	    	public static String reverseString(String s) {
	    		StringBuilder sb = new StringBuilder(s);
	    		sb.reverse();
	    		return (sb.toString());
	    	}
	    	
	    	public static long pow(long n, long p) {
	    		if(p==0)
	    			return 1;
	    		if(p==1)
	    			return n%mod;
	    		if(p%2==0){
	    			long temp=pow(n, p/2);
	    		return (temp*temp)%mod;
	    		}else{
	    			 	long temp=pow(n,p/2);
	    			 	temp=(temp*temp)%mod;
	    			 	return(temp*n)%mod;
	    			 	
	    		}
	    	}
	     
	    		
	    
	    	public static int nextPowerOf2(final int a) {
	    		int b = 1;
	    		while (b < a) {
	    			b = b << 1;
	    		}
	    		return b;
	    	}
	     
	    	public static boolean PointInTriangle(int p1, int p2, int p3, int p4, int p5, int p6, int p7, int p8) {
	    		int s = p2 * p5 - p1 * p6 + (p6 - p2) * p7 + (p1 - p5) * p8;
	    		int t = p1 * p4 - p2 * p3 + (p2 - p4) * p7 + (p3 - p1) * p8;
	     
	    		if ((s < 0) != (t < 0))
	    			return false;
	     
	    		int A = -p4 * p5 + p2 * (p5 - p3) + p1 * (p4 - p6) + p3 * p6;
	    		if (A < 0.0) {
	    			s = -s;
	    			t = -t;
	    			A = -A;
	    		}
	    		return s > 0 && t > 0 && (s + t) <= A;
	    	}
	     
	    	public static float area(int x1, int y1, int x2, int y2, int x3, int y3) {
	    		return (float) Math.abs((x1 * (y2 - y3) + x2 * (y3 - y1) + x3 * (y1 - y2)) / 2.0);
	    	}
	     
	    	public static boolean isPrime(int n) {
	    		// Corner cases
	    		if (n <= 1)
	    			return false;
	    		if (n <= 3)
	    			return true;
	     
	    		// This is checked so that we can skip 
	    		// middle five numbers in below loop
	    		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;
	    	}
	     
	    	//merge Sort
	     
	    	static long sort(int a[])
	    	{  int n=a.length;
	    		int b[]=new int[n];	
	    		return mergeSort(a,b,0,n-1);}
	    	static long mergeSort(int a[],int b[],long left,long right)
	    	{ long c=0;if(left<right)
	    	 {   long mid=left+(right-left)/2;
	    		 c= mergeSort(a,b,left,mid);
	    		 c+=mergeSort(a,b,mid+1,right);
	    		 c+=merge(a,b,left,mid+1,right); }	
	    		return c;	 }
	    	static long merge(int a[],int  b[],long left,long mid,long right)
	    	{long c=0;int i=(int)left;int j=(int)mid; int k=(int)left;
	    	while(i<=(int)mid-1&&j<=(int)right)
	    	{ if(a[i]>a[j]) {b[k++]=a[i++]; }
	    	else	{ b[k++]=a[j++];c+=mid-i;}}
	    	while (i <= (int)mid - 1)   b[k++] = a[i++]; 
	    	while (j <= (int)right) b[k++] = a[j++];
	    	for (i=(int)left; i <= (int)right; i++) 
	    		a[i] = b[i];  return c;  }
	    
	     
	    	// To Get Input
	    	// Some Buffer Methods
	     
	    	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 int[][] next2dArray(int n, int m) {
	    		int[][] arr = new int[n][m];
	    		for (int i = 0; i < n; i++) {
	    			for (int j = 0; j < m; j++) {
	    				arr[i][j] = nextInt();
	    			}
	    		}
	    		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);
	    	}
	private static ArrayList<Long> a;
	    
	    	//----------------------------------------My Code------------------------------------------------//
	    	private static void soln(){
hs=new HashSet<Long>();

a=new ArrayList<Long>();
	    		for(int i=0;i<=9;i++){
	    			for(int j=i+1;j<=9;j++){
	    				BFS((long)i,(long)j);
	    			}
	    		}
	    		
	    		int n=nextInt();
	    		long c=0;
	    		
	    		for(long x: hs){
	    			
	    			if(x<=n){
	    				c++;
	    			//	pw.println(x+"--");
	    				}
	    		}
	    		pw.println(c-1);
	    		

	    	
	    	}
	    	private static void BFS(long o,long t){
	    		Queue<Long> q=new LinkedList<Long>();
	    		q.add(o);
	    		q.add(t);
	    		hs.add(o);
	    		hs.add(t);
	    	
	    		while(!q.isEmpty()){
	    			 long no=q.poll();

	// System.out.println(no);
	    			
	    			 hs.add(no);
	    		if(((no*10)+o)<=1000000000 && no!=0)
	    			{
	    			q.add(((no*10) + o));
	    			//hs.add(no*10+o);
	    			}

	    		if((((no*10)+t))<=1000000000 && no!=0){
	    		q.add((no*10) + t);
	    		//hs.add(no*10+t);
	    		}
	    		}
	    		
	    	}
	    	
  		//-----------------------------------------The End--------------------------------------------------------------------------//

	    	    	
	    }
	    
		class Pair implements Comparable<Pair>{
		   
			String ind;
			int len;
			Pair(String ind,int len){
				this.ind=ind;
				this.len=len;
			}
			@Override
			public int compareTo(Pair o) {
				// TODO Auto-generated method stub
			//	Sort in increasing order
return len-o.len;
			}
		
		}
	        class Graph{
	        	private static int V,level[][],count=-1,lev_dfs[],degree=0,no_vert_conn_comp=0;
	        	private Stack <Integer>st=new Stack();
	        	private static LinkedList<Integer > adj[];
	        	private boolean[][] Visite;
	        	private static boolean [] Visited;
	        	private static HashSet<Integer> Vis=new HashSet();
	        	private static Stack<Integer> topo_sort=new Stack<>();
	        	private static HashMap<String,Integer> hm=new HashMap<>();
	        	private static int start_v=0;
	        	private static HashSet<String> ed=new HashSet<>();
	        	private static int red_ed[];
	  
		    
		    	
	    Graph(int V){
	    V++;
	    this.V=(V);
	    adj=new LinkedList[V];
	    Visite=new boolean[100][100];
	    
 	    Visited=new boolean[V];
	    level=new int[100][100];
	    lev_dfs=new int[V];
	    Arrays.fill(lev_dfs, Integer.MAX_VALUE);
	   for(int i=0;i<V;i++)
		   adj[i]=new LinkedList<Integer>();
	red_ed=new int[V];
	    Arrays.fill(red_ed, Integer.MAX_VALUE);
	    }
	    void setup(int start){
	    	//HashMap<String,Integer> hm=new HashMap<>();
    	start_v=start;
	    }
	   void addEdge(int v,int w){
	    	
	    	if(adj[v]==null){
	    		adj[v]=new LinkedList();
	    	}
	    	adj[v].add(w);
	    	adj[w].add(v);
	     
	    	String s="";
	    	s+=(w)+" "+v;
	    	ed.add(s);
	    }
	   public static void dfs3(int sv,int dist,int red){
		   Visited[sv]=true;
		   red_ed[sv]=red;
		
		   lev_dfs[sv]=Math.min(lev_dfs[sv], dist);
		   for(int x:adj[sv]){
			   String s="";
			   s+=sv+" "+x;
			   if(!Visited[x]){
				   if(ed.contains(s)){
					   dfs3(x, dist+1, red+1);
					   start_v++;
				   }else{
					   dfs3(x,dist+1,red);
				   }
			   }
		   }
	   }
	  public static void happ(){
	/*  for(int x:red_ed){
			  System.out.print(x+" ");
		  }
		 
System.out.println("\n"+start_v);
for(int x:lev_dfs){
			  System.out.print(x+" ");
		  }
		  System.out.println();
	 */ ArrayList<Integer> a[]=new ArrayList[V];
		  for(int i=1;i<V;i++)
			  a[i]=new ArrayList<Integer>();
		  int min=Integer.MAX_VALUE;
		  int ans[]=new int[V];
		  for(int i=1;i<V;i++){
			int fin=start_v-2*red_ed[i]+lev_dfs[i];
			ans[i]=fin;
			min=Math.min(min, fin);
		  }
		  StringBuilder sb=new StringBuilder();
		  sb.append(min+"\n");
		  for(int i=1;i<V;i++){
			  if(ans[i]==min)
				  sb.append(i+" ");
		  }
		  System.out.println(sb);
	  }
	 public static void top_ans(){
	while(topo_sort.size()!=0)
{
	System.out.print(hm.get(topo_sort.peek()));
topo_sort.pop();
}
	
	 }
	 public static void topoSort(int startVert){
		 if(!Vis.contains(startVert)){
			 topoSortUtil(startVert);
		 }
	 }
	    public static void topoSortUtil(int curr_Vert){
	    	Vis.add(curr_Vert);
	    	Iterator<Integer> it=adj[curr_Vert].listIterator();
	    	
	    	while(it.hasNext()){
	    		int n=it.next();
	   // 		System.out.println(n);
	    		if(!Vis.contains(n)){
	    			topoSortUtil(n);
	    		}
	    		
	    	}
	    	topo_sort.push(curr_Vert);
	    }
	    
	    public static int BFS2(int startVert){
	    	Visited=new boolean[V];
	    	for(int i=1;i<V;i++){
	    		lev_dfs[i]=-1;
	    	}
	    //	System.out.println(startVert);
	    	Queue<Integer> q=new LinkedList<Integer>();
	    	q.add(startVert);
	    	Visited[startVert]=true;
	    	lev_dfs[startVert]=0;
	    	while(!q.isEmpty()){
	    		int top=q.poll();
	    		
	    		Iterator<Integer> i= adj[top].listIterator();
	    		while(i.hasNext()){
	    			int n=i.next();
	    		
	    			if(!Visited[n]){
	    				q.add(n);
	    		//		System.out.println(top+" "+n);
	    				Visited[n]=true;
	    				lev_dfs[n]=lev_dfs[top]+1;
	    			
	    			}
	    		}
	    	}
	    
	    //	q.clear();
	    	int dis[]=new int[V];
	    
	    	for(int i=1;i<V;i++){
	    		int f=Integer.MAX_VALUE;
	    	for(int x:hs){
	    		if(Math.abs(lev_dfs[i]-lev_dfs[x])<f && lev_dfs[i]!=lev_dfs[x] && !hs.contains(i)){
	    		f=Math.abs(lev_dfs[i]-lev_dfs[x]);
	    	dis[i]=f;}
	    	}
	    	}
	    	
	    	for(int i=1;i<V;i++)
	    		System.out.print(dis[i]+" ");
	    //	System.out.println();
	    	return 0;
	    }
	    public int getEd(){
	    	return degree/2;
	    }
	  
	    private static boolean check(int x,int y,char c[][]){
		
			if((x>=0 && y>=0) && (x<c.length && y<c[0].length) && c[x][y]!='#'){
				
				return true;
			}
			return false;
		}
	    public int BFS(int x,int y,int k,char[][] c)
	    {
	    	 LinkedList<Pair> queue = new LinkedList<Pair>();
	        //Visited[s]=true;
	   //     queue.add(new Pair(x,y));
	       int count=0;
	   level[x][y]=-1;
	   c[x][y]='M';
	        while (!queue.isEmpty())
	        {
	            Pair temp = queue.poll();
	        
	            
	        }
	        return V;
	    }
	    static int ff=1;
	    static HashSet<Integer> hs;
	    static int pare=-1;
	    public static int dfs2Util(int sv,int pare){

	    	ff=1;
		    hs=new HashSet(); 
		    parent=new int[V];
		    Visited=new boolean[V];
		   if(dfs2(sv, pare)==-1)
			   return -1;
		   return 0;
		    
	    }
	    static int[] parent;
	   public static int dfs2(int sv,int pare){
		   Visited[sv]=true;
		//   System.out.println(sv+"-- "+pare);
		   parent[sv]=pare;
		   int flag=1;
		   for(int x:adj[sv]){
			   if(Visited[x] && start_v==x && x!=parent[sv]){
				   flag=0;
				////   break;  
				//   System.out.println(x+" "+sv);
				   hs.add(x);
			 while(parent[sv]!=0){
				 hs.add(sv);
				 sv=parent[sv];
				 
			 }
			 ff=0;
			break;
	}
			   
			   else if(!Visited[x] && ff==1){
				   pare=sv;
				   dfs2(x,pare);
				   }
		   }
	 
		  // System.out.println(pare);
		   if(ff==0)
			   return -1;
		   return 0;
	   }
	   public static void further()
	   {
		   StringBuilder sb=new StringBuilder();
		for(int x: hs){
			
		}
		
		/*   for(int i=1;i<V;i++){
		   if(hs.contains(i))
			   sb.append(0+" ");
		   else
			   sb.append(BFS2(i)+" ");
		   }
		   System.out.println(sb);*/
	   }	   
	    
	     public long dfs(int startVertex){
	    //	 getAns(startVertex);
	    	 Visited=new boolean[V];
	    	 if(!Visited[startVertex])  {
	    
	   return dfsUtil(startVertex);
	    	//return getAns();
	    	}
	    	 
	    
	     
	    return 0;
	    	}
	 private long dfsUtil(int startVertex) {
		 int c=1;
	
		 long cout=0;
	      degree=0;
	    	Visited[startVertex]=true;
	    	lev_dfs[startVertex]=0;
	      st.push(startVertex);
	      int temp=-1;
	      
	    while(!st.isEmpty()){
	    	
	    	int top=st.pop();
	  
	    	Iterator<Integer> i=adj[top].listIterator();
	     while(i.hasNext()){
	    //	System.out.println(top);
	    	int n=i.next();
	    	
	     if( !Visited[n]){
	    				Visited[n]=true;
	    				
	    			//	col_freq[col[n-1]]++;
	    				c++;
	    				st.push(n);
	    					lev_dfs[n]=lev_dfs[top]+1;
	    					
	    					
	    		 }
	         }
	 }
	 //   System.out.println(temp);
	 return c;
	    	
	    }
	        
	        }     
	       	        
	    class Dsu{
	    	private int rank[], parent[] ,n;
	    	
	    	Dsu(int size){
	    		this.n=size+1;
	    		rank=new int[n];
	    		parent=new int[n];
	    	makeSet();
	    	}
	    	
	    	void makeSet(){
	    		for(int i=0;i<n;i++){
	    			parent[i]=i;
	    		}
	    	}
	    	
	    	int find(int x){
	    		if(parent[x]!=x){
	    			
	    			parent[x]=find(parent[x]);
	    		}
	    		return parent[x];
	    	}	
	    	
	    	void union(int x,int y){
	    		int xRoot=find(x);
	    		int yRoot=find(y);
	    		
	    		if(xRoot==yRoot)
	    			return;
	    		if(rank[xRoot]<rank[yRoot]){
	    		parent[xRoot]=yRoot;	
	    		}else if(rank[yRoot]<rank[xRoot]){
	    			parent[yRoot]=xRoot;
	    		}else{
	    			parent[yRoot]=xRoot;
	    			rank[xRoot]++;
	    		}
	    		
	    	}
	     
	    }
	    class Heap{
	    	
	    	public static void build_max_heap(long []a,int size){
	    		
	    		for(int i=size/2;i>0;i--){
	    			max_heapify(a, i,size);
	    		}
	    		
	    			}
	    	private static void max_heapify(long[] a,int i,int size){
	    		int left_child=2*i;
	    		int right_child=(2*i+1);
	    		int largest=0;
	    		
	    		if(left_child<size && a[left_child]>a[i]){
	    			largest=left_child;
	    		}else{
	    			largest=i;
	    		}
	    		
	    		if(right_child<size && a[right_child]>a[largest]){
	    			largest=right_child;
	    		}
	    		if(largest!=i){
	    			long temp=a[largest];
	    			a[largest]=a[i];
	    			a[i]=temp;
	    			max_heapify(a, largest,size);
	    		}
	    	}
	    	private static void min_heapify(int[] a,int i){
	    		int left_child=2*i;
	    		int right_child=(2*i+1);
	    		int largest=0;
	    		
	    		if(left_child<a.length && a[left_child]<a[i]){
	    			largest=left_child;
	    		}else{
	    			largest=i;
	    		}
	    		
	    		if(right_child<a.length && a[right_child]<a[largest]){
	    			largest=right_child;
	    		}
	    		if(largest!=i){
	    			int temp=a[largest];
	    			a[largest]=a[i];
	    			a[i]=temp;
	    			min_heapify(a, largest);
	    		}
	    	}
	    	public static void extract_max(int size,long a[]){
	    		if(a.length>1){
	    			long max=a[1];
	    			a[1]=a[a.length-1];
	    			size--;
	    			max_heapify(a, 1,a.length-1);
	    		}
	    	}
	    }
	    
	    class MyComp implements Comparator<Long>{
	        
			@Override
			public int compare(Long o1, Long o2) {
				if(o1<o2){
					return 1;
				}else if(o1>o2){
					return -1;
				}
				return 0;
				
			}
	    }