#include <bits/stdc++.h>

#define N 100005
using namespace std;

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

void dfs(int s) {
    o[s] = true;

    euler[++nr] = s;
    for (int x : G[s])
        if (!o[x]) {
            height[x] = height[s] + 1;
            dfs(x);
            euler[++nr] = s;
        }
}

void rmq() {
    int i, j;
    unsigned int 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 (height[r[i][j - 1]] < height[r[i + p][j - 1]])
                r[i][j] = r[i][j - 1];
            else
                r[i][j] = r[i + p][j - 1];

    // compute log array
    p = 1;
    int l = -1;
    for (i = 1; i <= nr; i++) {
        if (i == p) l++, p <<= 1;
        lg[i] = l;
    }
}

int lca(int x, int y) {
    int l = lg[y - x + 1];

    if (height[r[x][l]] < height[r[y - (1 << l) + 1][l]])
        return r[x][l];
    return r[y - (1 << l) + 1][l];
}

int main() {
    ifstream cin("lca.in");
    ofstream cout("lca.out");

    int i, t;
    cin >> n >> m;
    for (i = 2; i <= n; i++) {
        cin >> t;
        G[t].push_back(i);
    }
    dfs(1);

    for (i = nr; i >= 1; i--) first[euler[i]] = i;

    rmq();

    int x, y;
    while (m--) {
        cin >> x >> y;
        cout << lca(min(first[x], first[y]), max(first[x], first[y])) << '\n';
    }
    return 0;
}