#include <bits/stdc++.h>

using namespace std;

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

int n, m, tour;
vector<int> eulerTour, depth;
vector<int> L[100005];
unordered_map<int, int> first;
int e[200005], rmq[18][200005], pows[20];

void EulerTour(int k, int adancime) {

    depth.push_back(adancime);
    eulerTour.push_back(k);
    first[k] = eulerTour.size() - 1;

    for (auto &w : L[k]) {
        EulerTour(w, adancime + 1);

        depth.push_back(adancime);
        eulerTour.push_back(k);
    }
}

void BuildRMQ() {
    for (int i = 2; i <= tour; i++) {
        e[i] = 1 + e[i / 2];
    }
    pows[0] = 1;
    for (int i = 1; i <= e[tour]; i++) {
        pows[i] = 2 * pows[i - 1];
    }

    for (int i = 1; i <= tour; i++) {
        rmq[0][i] = i;
    }
    int A, B;
    for (int i = 1; i <= e[tour]; i++) {
        for (int j = 1; j <= tour - pows[i] + 1; j++) {
            A = rmq[i - 1][j]; B = rmq[i - 1][j + pows[i - 1]];
            if (depth[A] < depth[B]) {
                rmq[i][j] = A;
            }
            else {
                rmq[i][j] = B;
            }
        }
    }
}

int Query(int u, int v) {
    int l, r, length, expo, pow, A, B;
    l = first[u]; r = first[v];
    if (r < l) swap(r, l);
    length = r - l + 1;
    expo = e[length];
    pow = pows[expo];
    A = rmq[expo][l]; B = rmq[expo][r - pow + 1];
    if (depth[A] < depth[B]) {
        return eulerTour[A];
    }
    return eulerTour[B];
}



int main() {
    int u, v;
    fin >> n >> m;
    for (int i = 2; i <= n; i++) {
        fin >> u;
        L[u].push_back(i);
    }

    eulerTour.push_back(-1);
    depth.push_back(-1);
    EulerTour(1, 0);

    tour = eulerTour.size() - 1;
    BuildRMQ();
    for (int i = 1; i <= m; i++) {
        fin >> u >> v;
        fout << Query(u, v) << "\n";
    }
}