#include <bits/stdc++.h>

using namespace std;

vector<pair<int, int>> parcurgere;

void dfs(int node, const vector<vector<int>>& tree, int depth = 0) {
    parcurgere.emplace_back(depth, node);
    for (auto x : tree[node]) {
        dfs(x, tree, depth + 1);
        parcurgere.emplace_back(depth, node);
    }
}

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

    int n, m;
    cin >> n >> m;

    vector<vector<int>> tree(n + 1);
    for (int i = 2; i <= n; i++) {
        int x;
        cin >> x;
        tree[x].push_back(i);
    }

    dfs(1, tree);

    vector<int> poz_parcurgere(n+1);
    for (int i = 0; i < parcurgere.size(); i++) {
        poz_parcurgere[parcurgere[i].second] = i;
    }

    vector<vector<pair<int, int>>> rmq(__lg(n) + 1);
    rmq[0] = move(parcurgere);

    int size = rmq[0].size();

    for (int i = 1; i < rmq.size(); i++) {
        int offset = 1 << (i - 1);
        rmq[i].resize(size);
        for (int j = 0; j + offset < size; j++) {
            rmq[i][j] = min(rmq[i-1][j], rmq[i-1][j + offset]);
        }
    }

    for (int i = 0; i < m; i++) {
        int a, b;
        cin >> a >> b;
        a = poz_parcurgere[a];
        b = poz_parcurgere[b];
        if (a > b)
            swap(a, b);
        int dist = b - a + 1;
        int max_pow = __lg(dist);
        
        cout << min(rmq[max_pow][a], rmq[max_pow][b - (1 << max_pow) + 1]).second << endl;
    }

}