#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <cctype>
#include <cmath>
#include <string>
#include <algorithm>
#include <vector>
#include <queue>
#include <deque>
#include <set>
#include <stack>
#include <cassert>
using namespace std;

#define PRO "lca"
void OpenFiles(int EVAL)
{
	if(EVAL)
	{
		char input[100] = PRO, output[100] = PRO;
		freopen(strcat(input, ".in"),"r",stdin);
		freopen(strcat(output,".out"),"w",stdout);
	} else
	{
		freopen("test.in","r",stdin);
		freopen("test.out","w",stdout);
	}
}

#define MAX  100001
#define INF 0xffffff

vector<int>g[MAX];

int n,pos[MAX],lca[2*MAX],niv[2*MAX],c[2*MAX][20],k;

void dfs(int x,int r)
{
	lca[++k] = x;
	niv[k] = r;
	for(int i=0;i<g[x].size();i++)
	{
		dfs(g[x][i],r+1);
		lca[++k] = x;
		niv[k] = r;
	}
}

void rmq()
{
	for(int j=1;(1<<j)<=k;j++)
		for(int i=1;i+(1<<j)-1<=k;i++)
			if( niv[c[i][j-1]] < niv[c[i+(1<<(j-1))][j-1]] )
				c[i][j] = c[i][j-1]; else
				c[i][j] = c[i+(1<<(j-1))][j-1];
}

int main(int argv,char *args[])
{
	OpenFiles(argv==0);
	// start
	int m,x,y;
		scanf("%d %d",&n,&m);
		for(int i=2;i<=n;i++)
		{
			scanf("%d",&x);
			g[x].push_back(i);
		}
		dfs(1,0);
		for(int i=1;i<=k;i++) c[i][0] = i;
		rmq();
		//for(int i=1;i<=2*n;i++)
		//{
		//	for(int j=0;j<=2*n;j++)printf("%d ",c[i][j]);
		//	printf("\n");
		//}
		for(int i=1;i<=k;i++)
			if(!pos[lca[i]])pos[lca[i]]=i;
		int k;
		for(int i=1;i<=m;i++)
		{
			scanf("%d %d",&x,&y);
			x = pos[x],y = pos[y];
			if(x>y)swap(x,y);
			k=log(double(y-x+1))/log(double(2));
			if( niv[c[x][k]] < niv[c[y-(1<<k)+1][k]] )
				printf("%d\n",lca[c[x][k]]); else
				printf("%d\n",lca[c[y-(1<<k)+1][k]]);
		}

	return 0;
}