#include <bits/stdc++.h>
#define MAX 100100

using namespace std;

ifstream f("lca.in");
ofstream g("lca.out");

int n, m, t[MAX], lvl[MAX];

void facemlca (int a, int b){
    while (t[a] != t[b]){
        if (lvl[a] > lvl[b]){
            a = t[a];
        } else {
            b = t[b];
        }
    }
    while (a != b){
        if (lvl[a] > lvl[b]){
            a = t[a];
        } else {
            b = t[b];
        }
    }
    g << a << '\n';
}

int main()
{
    ios_base::sync_with_stdio(false);
    f >> n >> m;
    lvl[1] = 1;
    for (int i = 1; i <= n-1; i++){
        int x;
        f >> x;
        t[i+1] = x;
        lvl[i+1] = lvl[x] + 1;
    }

    while (m--){
        int a, b;
        f >> a >> b;
        facemlca (a,b);
    }
    return 0;
}