#include <fstream>
#include <vector>

using namespace std;

ifstream cin ("lca.in");
ofstream cout ("lca.out");

int rmq[20][200100];
int LOG[200100];

vector < vector < int > > gr (100100);
vector < int > lv (100100);
vector < int > pos (100100);
vector < int > euler;

void dfs(int root){

    euler.push_back(root);
    pos[root] = euler.size()-1;

    for (auto &x : gr[root]){
        lv[x] = lv[root] + 1;
        dfs(x);
        euler.push_back(root);
    }

}

int main() {

    ios::sync_with_stdio(false);
    cin.tie(NULL);
    cout.tie(NULL);

    //rmq

    int n , m;
    cin>>n>>m;

    for (int i=2; i<=2*n; i++){
        LOG[i] = LOG[i/2] + 1;
    }

    for (int i=2; i<=n; i++){
        int dad;
        cin>>dad;
        gr[dad].push_back(i);
    }

    dfs(1);

    for (int i=0; i<euler.size(); i++){
        rmq[0][i] = euler[i];
    }

    for (int bit=1; bit<=LOG[2*n]; bit++){
        for (int i=0; i<euler.size(); i++){
            if (lv[rmq[bit-1][i]] < lv[rmq[bit-1][i + (1 << (bit - 1))]]){
                rmq[bit][i] = rmq[bit-1][i];
            }
            else{
                rmq[bit][i] = rmq[bit-1][i + (1 << (bit - 1))];
            }
        }
    }

    for (int i=1; i<=m; i++){
        int x , y;
        cin>>x>>y;

        x = pos[x];
        y = pos[y];

        if (y < x){
            int aux = y;
            y = x;
            x = aux;
        }

        int dif = y - x + 1;
        int l = LOG[dif];

        if (lv[rmq[l][x]] < lv[rmq[l][y - (1 << l) + 1]]){
            cout<<rmq[LOG[dif]][x];
        }
        else{
            cout<<rmq[LOG[dif]][y - (1 << l) + 1];
        }
        cout<<'\n';

    }

    return 0;
}