/// http://www.infoarena.ro/problema/lca

#include <cstdio>
#include <algorithm>
#include <vector>
using namespace std;

const int nmax = 100005, logmax = 20;

int nrE, N, Q;
int A[nmax * 2], E[nmax * 2], Log[nmax * 2], H[nmax], D[nmax * 4][logmax];
vector <int> C[nmax];

void Euler (int nod, int niv) {
    E[++nrE] = nod;
    A[nrE] = niv;
    H[nod] = nrE;
    for (size_t i = 0; i < C[nod].size(); i++) {
        Euler(C[nod][i], niv + 1);
        E[++nrE] = nod;
        A[nrE] = niv;
    }
}

void build() {
    Log[1] = 0;
    for (int i = 2; i <= nrE; i++)
        Log[i] = Log[i / 2] + 1;
    for (int i = 1; i <= nrE; i++)
        D[i][0] = i;
    for (int j = 1; (1 << j) <= nrE; j++)
        for (int i = 1; i + (1 << j) - 1 <= nrE; i++)
            if (A[D[i][j - 1]] < A[D[i + (1 << (j - 1))][j - 1]]) D[i][j] = D[i][j - 1];
            else D[i][j] = D[i + (1 << (j - 1))][j - 1];
}
int query(int x, int y) {
    int i = H[min(x, y)], j = H[max(x, y)], k = Log[j - i + 1];
    if (A[D[i][k]] <= A[D[j - (1 << k) + 1][k]]) return D[i][k];
    else return D[j - (1 << k) + 1][k];
}

int main() {
    FILE *in = fopen("lca.in", "r"), *out = fopen("lca.out", "w");
    if (in && out) {
        fscanf(in, "%d %d", &N, &Q);
        int x, y, root = 1;
        for(int i = 2; i <= N; i++) {
            fscanf(in, "%d", &x);
            C[x].push_back(i);
        }
        Euler(root, 0);
        build();
        for(int i = 0; i < Q; i++) {
            fscanf(in, "%d %d\n", &x, &y);
            fprintf(out, "%d\n", E[query(x, y)]);
        }
        fclose(in);
        fclose(out);
    }
    return 0;
}