#include <vector>
#include <iostream>
#include <fstream>
using namespace std;

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

int n, m, K, L[200001], H[200001], Lg[200001], First[100001], Rmq[20][400001];
vector <int> G[100001];

void euler(int nod, int niv) {
    H[++K] = nod;
    L[K] = niv;
    First[nod] = K;

    for(typeof (G[nod]).begin() it = (G[nod]).begin(); it != (G[nod]).end(); ++it) {
        euler(*it, niv + 1);
        H[++K] = nod;
        L[K] = niv;
    }
}

void rmq() {
    for(int i = 2; i <= K; ++i)
        Lg[i] = Lg[i >> 1] + 1;
    for(int i = 1; i <= K; ++i)
        Rmq[0][i] = i;

    for(int i = 1; (1 << i) < K; ++i)
        for(int j = 1; j <= K - (1 << i); ++j)
        {
            int l = 1 << (i - 1);

            Rmq[i][j] = Rmq[i-1][j];
            if(L[Rmq[i-1][j + l]] < L[Rmq[i][j]])
                Rmq[i][j] = Rmq[i-1][j + l];
        }
}

int main() {
    f >> n >> m;
    for(int i = 2; i <= n; ++i) {
        int x;
        f >> x;
        G[x].push_back(i);
    }
    euler(1, 0);
    rmq();

    for (int i = 1; i <= m; i++) {
        int x, y;
        f >> x >> y;
        int dif, l, sol, sh;
        int a = First[x], b = First[y];
        if(a > b) {
            int aux = a;
            a = b;
            b = aux;
        }
        dif = b - a + 1;
        l = Lg[dif];
        sol = Rmq[l][a];
        sh = dif - (1 << l);
        if(L[sol] > L[Rmq[l][a + sh]])
            sol = Rmq[l][a + sh];
        g << H[sol] << '\n';
    }

    return 0;
}