#include <bits/stdc++.h>

#define N 100002

using namespace std;

int n, m, euler[2 * N], nr, first[N], h[N], r[2 * N][30], lg[2 * N];
vector<int> G[N];

void DFS(int s, int p) {
    euler[++nr] = s;
    for (int x : G[s])
        if (x != p) {
            h[x] = h[s] + 1;
            DFS(x, s);
            euler[++nr] = s;
        }
}

void rmq() {
    int i, j, p;
    for (i = 1; i <= nr; i++)
        r[i][0] = euler[i];

    for (j = 1, p = 1; p << 1 < nr; j++, p <<= 1)
        for (i = 1; i <= nr - (p << 1) + 1; i++)
            if (h[r[i][j - 1]] < h[r[i + p][j - 1]])
                r[i][j] = r[i][j - 1];
            else
                r[i][j] = r[i + p][j - 1];

    j = 0;
    for (i = 1, p = 2; i <= nr; i++) {
        if (i == p) j++, p <<= 1;
        lg[i] = j;
    }
}

int lca(int x, int y) {
    int l = lg[y - x + 1];
    if (h[r[x][l]] < h[r[y - (1 << l) + 1][l]])
        return r[x][l];
    return r[y - (1 << l) + 1][l];
}

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

    int i, x, y;
    fin >> n >> m;
    for (i = 2; i <= n; i++) {
        fin >> x;
        G[x].push_back(i);
    }

    DFS(1, 0);
    for (i = nr; i >= 0; i--)
        first[euler[i]] = i;
    rmq();

    while (m--) {
        fin >> x >> y;
        fout << lca(min(first[x], first[y]), max(first[x], first[y])) << '\n';
    }

    return 0;
}