#include <bits/stdc++.h>

using namespace std;

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

const int NMax = 100005;

vector<int> G[NMax];
bitset<NMax> viz;
int key[NMax];
pair<int, int> rmq[24][4 * NMax];
int sz;

void DFS(int nod, int depth){
    viz[nod] = 1;
    key[nod] = ++ sz;
    rmq[0][sz] = make_pair(depth, nod);
    for(int i = 0; i < G[nod].size(); ++ i){
        int vecin = G[nod][i];
        if(viz[vecin] == 0){
            DFS(vecin, depth + 1);
            rmq[0][++ sz] = make_pair(depth, nod);
        }
    }
}

int query(int a, int b){
    if(a > b){
        swap(a, b);
    }
    pair<int, int> ans = make_pair((1 << 31) - 1, (1 << 31) - 1);
    int l = b - a + 1;
    for(int i = 24; i >= 0; -- i){
        if((1 << i) <= l){
            l -= (1 << i);
            ans = min(ans, rmq[i][a]);
            a += (1 << i);
        }
    }
    return ans.second;
}

int main()
{
    int N, M;
    fin >> N >> M;
    for(int x, i = 2; i <= N; ++ i){
        fin >> x;
        G[x].push_back(i);
    }
    DFS(1, 0);
    for(int i = 1; (1 << i) <= sz; ++ i){
        for(int j = 1; (j + (1 << i)) - 1 <= sz; ++ j){
            rmq[i][j] = min(rmq[i - 1][j], rmq[i - 1][j + (1 << (i - 1))]);
        }
    }
    for(int x, y, i = 1; i <= M; ++ i){
        fin >> x >> y;
        fout << query(key[x], key[y]) << '\n';
    }
    return 0;
}