#include <bits/stdc++.h>
using namespace std;

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

int n, len;
vector<vector<int>> ad;
vector<int> arr, dpt, pos;

void dfs(int node, int depth) {
    arr[++len] = node; pos[node] = len; dpt[len] = depth;
    for (int nghb : ad[node]) {
        dfs(nghb, depth + 1);
        arr[++len] = node; dpt[len] = depth;
    }
}

int main() {
    int q; fin >> n >> q;
    ad.resize(n + 1);
    for (int i = 2; i <= n; i++) {
        int x; fin >> x;
        ad[x].push_back(i);
    }

    arr.resize(2 * n);
    dpt.resize(2 * n);
    pos.resize(n + 1);
    dfs(1, 1);

    vector<vector<int>> dp(log2(len) + 1, vector<int>(len + 1));
    for (int i = 1; i <= len; i++)
        dp[0][i] = i;

    for (int i = len - 1; i >= 1; i--)
        for (int j = 1; i + (1 << j) - 1 <= len; j++)
            if (dpt[dp[j - 1][i]] < dpt[dp[j - 1][i + (1 << (j - 1))]])
                dp[j][i] = dp[j - 1][i];
            else
                dp[j][i] = dp[j - 1][i + (1 << (j - 1))];

    auto rmq = [&](int left, int right) {
        int len = right - left + 1;
        int log = log2(len);
        if (dpt[dp[log][left]] < dpt[dp[log][right - (1 << log) + 1]])
            return dp[log][left];
        return dp[log][right - (1 << log) + 1];
    };

    auto lca = [&](int x, int y) {
        x = pos[x], y = pos[y];
        if (x > y) swap(x, y);
        return arr[rmq(x, y)];
    };

    for (int i = 0; i < q; i++) {
        int x, y; fin >> x >> y;
        fout << lca(x, y) << '\n';
    }

    fout.close();
    return 0;
}