Sagheer is playing a game with his best friend Soliman. He brought a tree with n nodes numbered from 1 to n and rooted at node 1. The i-th node has ai apples. This tree has a special property: the lengths of all paths from the root to any leaf have the same parity (i.e. all paths have even length or all paths have odd length).

Sagheer and Soliman will take turns to play. Soliman will make the first move. The player who can't make a move loses.

In each move, the current player will pick a single node, take a non-empty subset of apples from it and do one of the following two things:

  1. eat the apples, if the node is a leaf. 
  2. move the apples to one of the children, if the node is non-leaf. 



Before Soliman comes to start playing, Sagheer will make exactly one change to the tree. He will pick two different nodes u and v and swap the apples of u with the apples of v.

Can you help Sagheer count the number of ways to make the swap (i.e. to choose u and v) after which he will win the game if both players play optimally? (u, v) and (v, u) are considered to be the same pair.

Input

The first line will contain one integer n (2 ≤ n ≤ 105) — the number of nodes in the apple tree.

The second line will contain n integers a1, a2, ..., an (1 ≤ ai ≤ 107) — the number of apples on each node of the tree.

The third line will contain n - 1 integers p2, p3, ..., pn (1 ≤ pi ≤ n) — the parent of each node of the tree. Node i has parent pi (for 2 ≤ i ≤ n). Node 1 is the root of the tree.

It is guaranteed that the input describes a valid tree, and the lengths of all paths from the root to any leaf will have the same parity.

Output

On a single line, print the number of different pairs of nodes (u, v), u ≠ v such that if they start playing after swapping the apples of both nodes, Sagheer will win the game. (u, v) and (v, u) are considered to be the same pair.

Examples

Input

3
2 2 3
1 1


Output

1


Input

3
1 2 3
1 1


Output

0


Input

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


Output

4

Note

In the first sample, Sagheer can only win if he swapped node 1 with node 3. In this case, both leaves will have 2 apples. If Soliman makes a move in a leaf node, Sagheer can make the same move in the other leaf. If Soliman moved some apples from a root to a leaf, Sagheer will eat those moved apples. Eventually, Soliman will not find a move.

In the second sample, There is no swap that will make Sagheer win the game.

Note that Sagheer must make the swap even if he can win with the initial tree.

import java.util.*;
import java.io.*;
import java.math.BigInteger;

/**
 *
 * @author usquare
 */

public class Problem{
    
    static int mod = (int) (1e9+7);
    static InputReader in;
    static PrintWriter out;
    static int[] arr;
    static int[] level;
    static ArrayList<Integer>[] g;
    static int xor;
    static int state;
    static HashMap<Integer,Integer>[] cnt;
    
    static void dfs(int u){
        HashMap<Integer,Integer> map=cnt[(level[u]&1)];
        int c=1;
        if(map.containsKey(arr[u])) c+=map.get(arr[u]);
        map.put(arr[u], c);
        
        for(int v:g[u]){
            level[v]=level[u]+1;
            dfs(v);
        }
        if(g[u].size()==0) state=(level[u]&1);
    }
    
    public static void main(String[] args) throws FileNotFoundException {
 
        in = new InputReader(System.in);
        out = new PrintWriter(System.out);            
        
        int n=in.ni();
        g=new ArrayList[n];
        level=new int[n];
        cnt=new HashMap[2];
        for(int i=0;i<n;i++) g[i]=new ArrayList<>();
        arr=in.nextIntArray(n);
        cnt[0]=new HashMap<Integer, Integer>();
        cnt[1]=new HashMap<Integer, Integer>();
        
        for(int i=1;i<n;i++){
            int p=in.ni()-1;
            g[p].add(i);
        }
        dfs(0);
        
        for(int i=0;i<n;i++){
            if((level[i]&1)==state) xor^=arr[i];
        }
        long ans=0;
        
        for(int i:cnt[state].keySet()){
            int tmp=xor^i;
            if(cnt[1^state].containsKey(tmp)){
                ans+=cnt[state].get(i)*(long)(cnt[1^state].get(tmp));
            }
        }
        
        if(xor==0){
            long tmp=0;
            for(int i:cnt[state].keySet())
                tmp+=cnt[state].get(i);
            ans+=(tmp*(tmp-1))/2;
            tmp=0;
            for(int i:cnt[1^state].keySet())
                tmp+=cnt[1^state].get(i);
            ans+=(tmp*(tmp-1))/2;
        }
        
        out.println(ans);
        out.close();
    }
    

    static class Pair implements Comparable<Pair>{

        int x;
        int y,i;
        
	Pair (int x,int y,int i){
		this.x=x;
		this.y=y;
		this.i=i;
	}

	Pair (int x,int y){
		this.x=x;
		this.y=y;
	}
        
	public int compareTo(Pair o) {
            return Long.compare(this.y,o.y);
		//return 0;
	}

            public boolean equals(Object o) {
            if (o instanceof Pair) {
                Pair p = (Pair)o;
                return p.x == x && p.y == y && p.i==i;
            }
            return false;
        }

        @Override
        public String toString() {
            return x+" "+y+" "+i;
        }
        
    } 
    
    static class Merge {
        
        public static void sort(long inputArr[]) {
            int length = inputArr.length;
            doMergeSort(inputArr,0, length - 1);
        }
        
        private static void doMergeSort(long[] arr,int lowerIndex, int higherIndex) {        
            if (lowerIndex < higherIndex) {
                int middle = lowerIndex + (higherIndex - lowerIndex) / 2;
                doMergeSort(arr,lowerIndex, middle);
                doMergeSort(arr,middle + 1, higherIndex);
                mergeParts(arr,lowerIndex, middle, higherIndex);
            }
        }
        
        private static void mergeParts(long[]array,int lowerIndex, int middle, int higherIndex) {
            long[] temp=new long[higherIndex-lowerIndex+1];
            for (int i = lowerIndex; i <= higherIndex; i++) {
                temp[i-lowerIndex] = array[i];
            }
            int i = lowerIndex;
            int j = middle + 1;
            int k = lowerIndex;
            while (i <= middle && j <= higherIndex) {
                if (temp[i-lowerIndex] < temp[j-lowerIndex]) {
                    array[k] = temp[i-lowerIndex];
                    i++;
                } else {
                    array[k] = temp[j-lowerIndex];
                    j++;
                }
                k++;
            }
            while (i <= middle) {
                array[k] = temp[i-lowerIndex];
                k++;
                i++;
            }
            while(j<=higherIndex){
                array[k]=temp[j-lowerIndex];
                k++;
                j++;
            }
        }

    }
    
    static long add(long a,long b){
        long x=(a+b);
        while(x>=mod) x-=mod;
        return x;
    }

    static long sub(long a,long b){
        long x=(a-b);
        while(x<0) x+=mod;
        return x;
    }
    
    static long mul(long a,long b){
        a%=mod;
        b%=mod;
        long x=(a*b);
        return x%mod;
    }

    
    static boolean isPal(String s){
        for(int i=0, j=s.length()-1;i<=j;i++,j--){
                if(s.charAt(i)!=s.charAt(j)) return false;
        }
        return true;
    }
    static String rev(String s){
		StringBuilder sb=new StringBuilder(s);
		sb.reverse();
		return sb.toString();
    }
    
    static long gcd(long x,long y){
	if(x%y==0)
		return y;
	else
		return gcd(y,x%y);
    }
    
    static int gcd(int x,int y){
	if(x%y==0)
		return y;
	else 
		return gcd(y,x%y);
    }
    
    static long gcdExtended(long a,long b,long[] x){
        
        if(a==0){
            x[0]=0;
            x[1]=1;
            return b;
        }
        long[] y=new long[2];
        long gcd=gcdExtended(b%a, a, y);
        
        x[0]=y[1]-(b/a)*y[0];
        x[1]=y[0];
        
        return gcd;
    }
    

    static long mulmod(long  a,long b,long m) {
        if (m <= 1000000009) return a * b % m;
 
        long res = 0;
        while (a > 0) {
            if ((a&1)!=0) {
                res += b;
                if (res >= m) res -= m;
            }
            a >>= 1;
            b <<= 1;
            if (b >= m) b -= m;
        }
        return res;
    }
    
    static int abs(int a,int b){
	return (int)Math.abs(a-b);
    }

    public static long abs(long a,long b){
	return (long)Math.abs(a-b);
    }
    
    static int max(int a,int b){
	if(a>b)
		return a;
	else
		return b;
    }

    static int min(int a,int b){
	if(a>b)
		return b;
	else 
		return a;
    }
    
    static long max(long a,long b){
	if(a>b)
		return a;
	else
		return b;
    }

    static long min(long a,long b){
	if(a>b)
		return b;
	else 
		return a;
    }

    static long pow(long n,long p,long m){
	 long  result = 1;
	  if(p==0)
	    return 1;
          
	while(p!=0)
	{
	    if(p%2==1)
	        result *= n;
	    if(result>=m)
	    result%=m;
	    p >>=1;
	    n*=n;
	    if(n>=m)
	    n%=m;
	}
	return result;
    }
    
    static long pow(long n,long p){
	long  result = 1;
	  if(p==0)
	    return 1;
          
	while(p!=0)
	{
	    if(p%2==1)
	        result *= n;	    
	    p >>=1;
	    n*=n;	    
	}
	return result;
    }
    
    static void debug(Object... o) {
            System.out.println(Arrays.deepToString(o));
    }
     
    static class InputReader {
    
        private final InputStream stream;
        private final byte[] buf = new byte[8192];
        private int curChar, snumChars;
        private SpaceCharFilter filter;

        public InputReader(InputStream stream) {
                this.stream = stream;
        }

        public int snext() {
                if (snumChars == -1)
                        throw new InputMismatchException();
                if (curChar >= snumChars) {
                        curChar = 0;
                        try {
                                snumChars = stream.read(buf);
                        } catch (IOException e) {
                                throw new InputMismatchException();
                        }
                        if (snumChars <= 0)
                                return -1;
                }
                return buf[curChar++];
        }

        public int ni() {
                int c = snext();
                while (isSpaceChar(c)) {
                        c = snext();
                }
                int sgn = 1;
                if (c == '-') {
                        sgn = -1;
                        c = snext();
                }
                int res = 0;
                do {
                        if (c < '0' || c > '9')
                                throw new InputMismatchException();
                        res *= 10;
                        res += c - '0';
                        c = snext();
                } while (!isSpaceChar(c));
                return res * sgn;
        }

        public long nl() {
                int c = snext();
                while (isSpaceChar(c)) {
                        c = snext();
                }
                int sgn = 1;
                if (c == '-') {
                        sgn = -1;
                        c = snext();
                }
                long res = 0;
                do {
                        if (c < '0' || c > '9')
                                throw new InputMismatchException();
                        res *= 10;
                        res += c - '0';
                        c = snext();
                } while (!isSpaceChar(c));
                return res * sgn;
        }

        public int[] nextIntArray(int n) {
                int a[] = new int[n];
                for (int i = 0; i < n; i++) {
                        a[i] = ni();
                }
                return a;
        }

        public long[] nextLongArray(int n) {
                long a[] = new long[n];
                for (int i = 0; i < n; i++) {
                        a[i] = nl();
                }
                return a;
        }

        public String readString() {
                int c = snext();
                while (isSpaceChar(c)) {
                        c = snext();
                }
                StringBuilder res = new StringBuilder();
                do {
                        res.appendCodePoint(c);
                        c = snext();
                } while (!isSpaceChar(c));
                return res.toString();
        }

        public String nextLine() {
                int c = snext();
                while (isSpaceChar(c))
                        c = snext();
                StringBuilder res = new StringBuilder();
                do {
                        res.appendCodePoint(c);
                        c = snext();
                } while (!isEndOfLine(c));
                return res.toString();
        }

        public boolean isSpaceChar(int c) {
                if (filter != null)
                        return filter.isSpaceChar(c);
                return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
        }

        private boolean isEndOfLine(int c) {
                return c == '\n' || c == '\r' || c == -1;
        }

        public interface SpaceCharFilter {
                public boolean isSpaceChar(int ch);
        }
        
    }
}    

