#include <bits/stdc++.h>

using namespace std;

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

const int NM = 2e5 + 5;

vector<int>g[NM];
int rmq[NM][18], sz, first[NM], k[NM], euler[NM];
int n, m;

void dfs (int nod, int dad =-1) {
    euler[++sz] = nod;
    if (first[nod] == 0) {
        first[nod] = sz;
    }
    for (int u : g[nod]) {
        if (u != dad) {
            dfs(u, nod);
            euler[++sz] = nod;
        }
    }
}

void precalc() {
    dfs(1);
    for (int i = 2; i < NM; i++) {
        k[i] = 1 + k[i / 2];
    }
    for (int i = 1; i <= sz; i++) {
        rmq[i][0] = euler[i];
    }
    for (int j = 1; j <= 18; j++) {
        for (int i = 1; i + (1 << j) - 1 <= sz; i++) {
            rmq[i][j] = min(rmq[i][j - 1], rmq[i + (1 << (j - 1))][j - 1]);
        }
    }
}

int solve (int l, int r) {
    l = first[l];
    r = first[r];
    int T = k[r - l + 1];
    return min(rmq[l][T], rmq[r - (1 << T) + 1][T]);
}

int main() {
    fin >> n >> m;
    for (int i = 2; i <= n; i++) {
        int x; fin >> x;
        g[x].push_back(i);
    }
    precalc();
    while (m--) {
        int l, r;
        fin >> l >> r;
        fout << solve(l, r) << '\n';
    }
}