#include <bits/stdc++.h>

#define NMAX 100005

using namespace std;

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

int N, M, level[NMAX], dad[NMAX], intervalDad[NMAX], H;
vector < int > graph[NMAX];

void readInput() {
    f >> N >> M;
    H = sqrt(N);
    for (int i = 2; i <= N; ++i) {
        f >> dad[i];
        graph[dad[i]].push_back(i);
    }
}

void dfs(int node, int intervalFather, int currentLevel) {
    level[node] = currentLevel;
    intervalDad[node] = intervalFather;

    if (currentLevel % H == 0) {
        intervalFather = node;
    }

    for (auto it : graph[node]) {
            dfs(it, intervalFather, currentLevel + 1);
    }
}

int lca(int node1, int node2) {
    /* Aduc nodurile in acelasi interval */
    while (intervalDad[node1] != intervalDad[node2]) {
        if (level[node1] > level[node2]) {
            node1 = intervalDad[node1];
        } else {
            node2 = intervalDad[node2];
        }
    }

    /* "Urc" in arbore cu fiecare nod pana cand acestea sunt egale */
    while (node1 != node2) {
        /* La fiecare pas, urc cu nodul care are nivelul mai mare*/
        if (level[node1] > level[node2]) {
            node1 = dad[node1];
        } else {
            node2 = dad[node2];
        }
    }

    return node1;
}

void computeQueries() {
    for (int i = 1; i <= M; ++i) {
        int node1, node2;
        f >> node1 >> node2;
        g << lca(node1, node2) << '\n';
    }
}

int main() {
    readInput();
    dfs(1, 0, 0);
    computeQueries();
    return 0;
}