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

#define pb push_back

ifstream f("lca.in");
ofstream g("lca.out");

const int N = 1e5 + 5;

int n, m, k, tata[N], first[N], nivel[N], rmq[18][2 * N];
vector<int> fii[N], stk;

void init(), read(), euler(), build_rmq(), solve_queries();

int main()
{
    init();
    solve_queries();
    return 0;
}

void init(){
    read();
    euler();
    build_rmq();
}
void read(){
    f >> n >> m;
    for (int i = 2; i <= n; i++) {
        f >> tata[i];
        fii[tata[i]].pb(i);
    }
}
void euler(){
    stk.pb(1); nivel[1] = 0;
    while (stk.size()){
        int nod = stk.back(); stk.pop_back();
        rmq[0][++k] = nod; if (!first[nod]) first[nod] = k;
        if (fii[nod].size()){
            int fiu = fii[nod].back(); fii[nod].pop_back();
            nivel[fiu] = nivel[nod] + 1; stk.pb(nod); stk.pb(fiu);
        }
    }
}
void build_rmq(){
    for (int i = 1, p = 2; p <= k; i++, p *= 2){
        for (int j = 1; j + p / 2 <= k; j++)
            if (nivel[rmq[i - 1][j]] < nivel[rmq[i - 1][j + p / 2]])
                rmq[i][j] = rmq[i - 1][j];
            else rmq[i][j] = rmq[i - 1][j + p / 2];
    }
}
void solve_queries(){
    int a, b;
    for (; m; m--){
        f >> a >> b;
        a = first[a]; b = first[b];
        if (a > b) swap(a, b);
        int l = b - a;
        l = 31 - __builtin_clz(l);
        if (nivel[rmq[l][a]] < nivel[rmq[l][b - (1 << l) + 1]]) g << rmq[l][a] << '\n';
        else g << rmq[l][b - (1 << l) + 1] << '\n';
    }
}