#include <fstream>
#include <vector>
using namespace std;
ifstream fin("lca.in");
ofstream fout("lca.out");

int n, m;
int anc[50][int(1e5) + 5];
int lg2[int(1e5) + 5];
int level[int(1e5) + 5];
bool marked[int(1e5) + 5];
vector<int> vecini[int(1e5) + 5];

void dfs(int node, int lv){

    level[node] = lv;
    marked[node] = true;

    for (int vec: vecini[node]){

        if (!marked[vec])
            dfs(vec, lv + 1);

    }
}

int transform(int x, int h){

    int y = log2(h);

    for(int add = y; add >= 0; add --)
        if(h >= (1 << add)){

            h -= (1 << add);
            x = anc[add][x];

        }

    return x;

}

int main(){

    fin >> n >> m;

    anc[0][1] = 0;
    for (int i = 2; i <= n; i++){
        fin >> anc[0][i];
        vecini[anc[0][i]].push_back(i);
    }

    dfs(1, 1);

    for (int exp = 1; (1 << exp) <= n; exp++){
        for (int i = 1; i <= n; i++){
            anc[exp][i] = anc[exp - 1][anc[exp - 1][i]];
        }
    }

    for (int i = 1; i <= m; i++){

        int a, b;
        fin >> a >> b;

        if (level[a] > level[b])
            swap(a, b);

        int level_diff = abs(level[a] - level[b]);

       b = transform(b, level_diff);

        if (a == b) {
            fout << a << '\n';
            continue;
        }

        for (int exp = 17; exp >= 0; exp --){

            if (anc[exp][a] != anc[exp][b]){
                a = transform(a, (1 << exp));
                b = transform(b, (1 << exp));
            }

        }

        fout << anc[0][a] << '\n';

    }

    return 0;
}