#include <fstream>
#include <vector>
using namespace std;

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

const int MAX = 1e5;

int poz[MAX+1] , niv[MAX+1], k , n , m , t , nivel , log[2*MAX+2] , a , b;

int rmq[18][2*MAX+2];

vector <int> g[MAX+1];

void dfseuler( int x ){

    ++nivel;

    niv[x] = nivel;

    rmq[0][++k] = x;

    poz[x] = k;

    for(auto it : g[x]){

        dfseuler(it);

        rmq[0][++k] = x;
    }

    --nivel;
}

// rmq[i][j] = minimul din intervalul (j , j + (1<<i) - 1)

int main(){

    cin >> n >> m;

    for(int i = 2 ; i <= n ; i++){

        cin >> t;

        g[t].push_back(i);
    }

    dfseuler(1);

    log[0] = -1;

    int ne = n*2 - 1;

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

        log[i] = log[i/2] + 1;
    }

    for(int i = 1 ; i <= log[ne] ; i++ ){

        for(int j = 1 ; j + (1<<i) - 1 <= ne ; j++){

            if(niv[rmq[i-1][j]] < niv[rmq[i-1][j+(1<<(i-1))]]){

                rmq[i][j] = rmq[i-1][j];

            }else rmq[i][j] = rmq[i-1][j+(1<<(i-1))];
        }
    }

    while(m--){

        cin >> a >> b;

        a = poz[a] , b = poz[b];

        if(b<a) swap(a,b);

        int l = b-a+1;

        l =log[l];

        cout << min(rmq[l][a],rmq[l][b-(1<<l)+1]) << '\n';
    }

    return 0;
}