#include <fstream>
#include <vector>
#include <cmath>
#define DIM 100002
#define ff first
#define ss second

using namespace std;

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

int n, q, t[DIM], k, put[DIM], x, y, l, d[20][DIM], nivel[DIM];

vector<int> arb[DIM];

void dfs(int nod, int niv){
    nivel[nod] = niv;
    for(int i = 0; i < arb[nod].size(); ++ i)
        dfs(arb[nod][i], niv + 1);
}

int main()
{
    f>>n>>q;
    for(int i = 2; i <= n; ++ i){
        f>>d[0][i];
        arb[d[0][i]].push_back(i);
    }

    dfs(1, 1);

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

    for(int i = 2; i <= n; ++ i)
        put[i] = put[i / 2];

    for(int i = 1; i <= q; ++ i){
        f>>x>>y;
        if(nivel[y] < nivel[x])
            swap(x, y);
        int dif = nivel[y] - nivel[x];
        if(dif != 0){
            while(dif){
                int putere = put[dif];
                y = d[putere][y];
                dif -= (1 << putere);
            }
        }
        if(x == y)
            g<<x<<'\n';
        else{
            while(x){
                int putere = put[x];
                x = d[putere][x];
                y = d[putere][y];
                if(x == y){
                    g<<x<<'\n';
                    break;
                }
            }
        }

    }




    return 0;
}