#include <iostream>
#include <fstream>
#include <vector>
#include <queue>
#include <utility>
#include <algorithm>
#include <functional>
#include <string>
#include <cstring>
#include <cmath>
#include <map>
#include <set>
#include <stack>
#define NMAX 100005
#define LOGMAX 18
#define MOD 666013
#define INF 0x3f3f3f3f
#define pb push_back

using namespace std;

typedef pair<int, int> pii;

FILE *fin = fopen("lca.in","r");
FILE *fout = fopen("lca.out","w");

int euler[2*NMAX],height[2*NMAX],firstap[NMAX], nrord, precalclog[NMAX];
int RMQ[LOGMAX][2*NMAX];
vector<int> v[NMAX];

void DFS(int x, int level);

int main() {
	int i,n,j,m,x,y,dif,k,ramas,res;

	fscanf(fin, "%d%d", &n, &m);
	for(i=2;i<=n;++i) {
		fscanf(fin, "%d", &x);
		v[x].pb(i);
	}

	DFS(1,0);

	for(i=2;i<=nrord;++i)
		precalclog[i]=precalclog[i/2]+1;

	for(i=1;i<=nrord;++i)
		RMQ[0][i]=i;

	for(i=1;(1<<i)<=nrord;++i)
		for(j=1;j+(1<<i)-1<=nrord;++j)
			if(height[RMQ[i-1][j]] < height[RMQ[i-1][j+(1<<(i-1))]])
				RMQ[i][j]=RMQ[i-1][j];
			else
				RMQ[i][j]=RMQ[i-1][j+(1<<(i-1))];

	for(i=0;i<m;++i) {
		fscanf(fin, "%d%d", &x, &y);
		x=firstap[x];
		y=firstap[y];

		if(x>y) swap(x,y);

		dif=y-x+1;
		k=precalclog[dif];
		ramas=dif-(1<<k);

		if(height[RMQ[k][x]] < height[RMQ[k][x+ramas]])
			res=RMQ[k][x];
		else res=RMQ[k][x+ramas];

		fprintf(fout,"%d\n", euler[res]);
	}

    return 0;
}

void DFS(int x, int level) {
	int i;

	euler[++nrord]=x;
	height[nrord]=level;
	firstap[x]=nrord;

	for(i=0;i<v[x].size();++i) {
		DFS(v[x][i],level+1);

		euler[++nrord]=x;
		height[nrord]=level;
	}
}