#include <iostream>
#include <fstream>
#include <vector>
#include <cmath>
#define MAX 100003

using namespace std;

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

vector<int> vec[MAX];
int euler[3*MAX];
int H[MAX];
int f[MAX];
int k=1;
pair<int, int> rmq[18][MAX*2];

void dfs(int nod, int niv) {
    euler[k] = nod;
    H[k] = niv;
    f[nod] = k;
    k++;
    for(vector<int>::iterator it = vec[nod].begin(); it != vec[nod].end(); it++) {
        dfs(*it, niv+1);
        euler[k] = nod;
        H[k] = niv;
        k++;
    }
}

void rm() {
    for(int i = 1; i < k; i++) {
        rmq[0][i].first = H[i];
        rmq[0][i].second = euler[i];
    }
    int lg = log2(k);
    for(int i = 1; i <= lg; i++)
        for(int j = 1; j < k; j++)
            rmq[i][j] = min(rmq[i-1][j], rmq[i-1][j+(1<<(i-1))]);
}

int query(int st, int dr) {
    if(st > dr)
        swap(st, dr);
    int diff = dr-st;
    int lg = log2(diff);
    return min(rmq[lg][st], rmq[lg][st-(1<<lg)+1]).second;
}

int main() {

    int n,m,x,y;
    in >> n >> m;

    for(int i = 2; i <= n; i++) {
        in >> x;
        vec[x].push_back(i);
    }

    dfs(1, 0);
    rm();

    for(int i = 1; i <= m; i++) {
        in >> x >> y;
        out << query(f[x], f[y]) << '\n';
    }

    return 0;
}