#include <bits/stdc++.h>
using namespace std;

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

const int maxn = 1e5 + 5;
const int maxlog = 20;
vector <int> G[maxn];
int Euler[maxn << 1], First[maxn], RMQ[maxlog][maxn << 2];
int Size;

void Dfs (int node) {
    Euler[++Size] = node;
    First[node] = Size;
    for (auto &it : G[node]) {
        Dfs(it);
        Euler[++Size] = node;
    }
}

int Lca (int x, int y) {
    int a = First[x];
    int b = First[y];
    if (a > b) {
        swap(a, b);
    }
    int k = log2(b - a + 1);
    return min(RMQ[k][a], RMQ[k][b - (1 << k) + 1]);
}

int main () {
    ios_base :: sync_with_stdio (false);
    int n, m, x, y, i, j;
    fin >> n >> m;
    for (i = 1; i < n; i++) {
        fin >> x;
        G[x].push_back(i + 1);
    }
    Dfs(1);
    for (i = 1; i <= Size; i++) {
        RMQ[0][i] = Euler[i];
    }
    for( i = 1; (1 << i) <= Size; i++) {
        for(j = 1; j + (1 << i) - 1 <= Size; j++) {
            RMQ[i][j] = min(RMQ[i - 1][j], RMQ[i - 1][j + (1 << (i - 1))]);
        }
    }
    while (m--) {
        fin >> x >> y;
        fout << Lca(x, y) << "\n";
    }
    fin.close();
    fout.close();
    return 0;
}