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

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

#define NMAX 100005

vector<int> G[NMAX];
int dp[20][4 * NMAX], log2[2 * NMAX];
int nivel[2 * NMAX], primul[NMAX];
int euler[2 * NMAX];
int k;

void dfs(int nod, int niv) {
    euler[++k] = nod;
    nivel[k] = niv;
    primul[nod] = k;

    for (auto it : G[nod]) {
        dfs(it, niv + 1);

        euler[++k] = nod;
        nivel[k] = niv;
    }
}

void rmq() {
    log2[1] = 0;
    for (int i = 2; i <= k; ++i) {
        log2[i] = log2[i / 2] + 1;
    }

    for (int i = 1; i <= k; ++i) {
        dp[0][i] = i;
    }

    for (int i = 1; (1 << i) <= k; ++i) {
        for (int j = 1; j + (1 << i) - 1 <= k; ++j) {
            int putere = (1 << (i - 1));
            if (nivel[dp[i - 1][j]] < nivel[dp[i - 1][j + putere]]) {
                dp[i][j] = dp[i - 1][j];
            } else {
                dp[i][j] = dp[i - 1][j + putere];
            }
        }
    }
}

int lca(int x, int y) {
    int a = primul[x], b = primul[y];

    if (a > b) {
        int aux = a;
        a = b;
        b = aux;
    }

    int dif = b - a + 1;
    int log = log2[dif];
    int putere = (1 << log);

    if (nivel[dp[log][a]] < nivel[dp[log][b - putere + 1]]) {
        return euler[dp[log][a]];
    } else {
        return euler[dp[log][b - putere + 1]];
    }
}

int main() {
    int n, m;
    fin >> n >> m;
    for (int i = 2; i <= n; ++i) {
        int x;
        fin >> x;

        G[x].push_back(i);
    }

    dfs(1, 0);

    rmq();

    while (m--) {
        int u, v;
        fin >> u >> v;

        fout << lca(u, v) << '\n';
    }
    return 0;
}