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

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

const int maxn = 1e5 + 5;
vector <int> G[maxn];
int P[maxn], H[maxn], T[maxn];

int Lca (int x, int y) {
    while(P[x] != P[y]) {
        if (H[x] > H[y]) x = P[x];
        else y = P[y];
    }
    while(x != y) {
        if(H[x] > H[y]) x = T[x];
        else y = T[y];
    }
    return x;
}

void Dfs(int node, int rad) {
    if (H[node] < rad) P[node] = 1;
    else if (H[node] % rad == 0) P[node] = T[node];
    else P[node] = P[T[node]];
    int i, son;
    for (auto &it : G[node]) {
        Dfs(it, rad);
    }
}

int main () {
    ios_base :: sync_with_stdio (false);
    int n, m, x, y, hmax = 0, i;
    fin >> n >> m;
    for (i = 2; i <= n; i++) {
        fin >> T[i];
        G[T[i]].push_back(i);
        H[i] = H[T[i]] + 1;
        hmax = max(hmax, H[i]);
    }

    Dfs(1, sqrt(hmax));
    for (i = 1; i <= m; i++) {
        fin >> x >> y;
        fout << Lca(x, y) << "\n";
    }
    fin.close();
    fout.close();
    return 0;
}