#include <fstream>
#include <vector>
#include <algorithm>
#include <cmath>

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

int const nmax = 100000;
int const pmax = 19;
std::vector <std::vector<int>> adj;
int ap[nmax + 5];
int rmq[pmax][nmax * 2 + 5];
int level[nmax + 5];
int n, m, eulerCnt;

void dfsEuler (int nod) {
    rmq[0][++eulerCnt] = nod;
    if (ap[nod] == 0)
        ap[nod] = eulerCnt;
    int lim = adj[nod].size ();
    for (int i = 0; i < lim; i++) {
        level[adj[nod][i]] = level[nod] + 1;
        dfsEuler (adj[nod][i]);
        rmq[0][++eulerCnt] = nod;
    }
}

void solvermq () {
    int log = log2(eulerCnt);
    for (int p = 1; p <= log; p++) {
        for (int i = 1; i <= eulerCnt - (1 << p) + 1; i++) {
            if (level[rmq[p - 1][i]] < level[rmq[p - 1][i + (1 << (p - 1))]])
                rmq[p][i] = rmq[p - 1][i];
            else
                rmq[p][i] = rmq[p - 1][i + (1 << (p - 1))];
        }
    }
}

int main() {
    fin >> n >> m;
    adj.resize (n + 1);
    for (int i = 2; i <= n; i++) {
        int x;
        fin >> x;
        adj[x].push_back (i);
    }
    level[1] = 1;
    dfsEuler (1);
    solvermq ();
    while (m--) {
        int x, y;
        fin >> x >> y;
        x = ap[x];
        y = ap[y];
        if (y < x)
            std::swap (x, y);
        int logDif = log2 (y - x + 1);
        if (level[rmq[logDif][x]] < level[rmq[logDif][y - (1 << logDif) + 1]])
            fout << rmq[logDif][x] << "\n";
        else
            fout << rmq[logDif][y - (1 << logDif) + 1] << "\n";
    }
}