#include<fstream>
#include<vector>
#define DIM 100005
using namespace std;
int n, i, ii, x, y, q, nr;
int a[18][2 * DIM], b[2 * DIM], frst[DIM], niv[DIM];
vector<int> v[DIM];
ifstream fin("lca.in");
ofstream fout("lca.out");
void dfs(int nod){
    a[0][++nr] = nod;
    frst[nod] = nr;
    for(int i = 0; i < v[nod].size(); i++){
        niv[ v[nod][i] ] = 1 + niv[nod];
        dfs(v[nod][i]);
        a[0][++nr] = nod;
    }
}
int lca(int x, int y){
    if(x > y){
        swap(x, y);
    }
    int p = b[y - x + 1];
    if(niv[ a[p][x] ] < niv[ a[p][y - (1 << p) + 1] ]){
        return a[p][x];
    }
    else{
        return a[p][y - (1 << p) + 1];
    }
}
int main(){
    fin>> n >> q;
    for(i = 2; i <= n; i++){
        fin>> x;
        v[x].push_back(i);
    }
    dfs(1);
    for(i = 2; i <= nr; i++){
        b[i] = b[i / 2] + 1;
    }
    for(ii = 1; (1 << ii) <= nr; ii++){
        for(i = 1; i <= nr - (1 << ii) + 1; i++){
            a[ii][i] = a[ii - 1][ i + (1 << (ii - 1) ) ];
            if(niv[ a[ii][i] ] > niv[ a[ii - 1][i] ]){
                a[ii][i] = a[ii - 1][i];
            }
        }
    }
    for(; q; q--){
        fin>> x >> y;
        fout<< lca(frst[x], frst[y]) <<"\n";
    }
    return 0;
}