#include <bits/stdc++.h>

using namespace std;

const int MAXN = 1000005;

int tata[MAXN], euler[4 * MAXN], nivel[MAXN];
vector<int> graf[MAXN];
int rmq[30][MAXN], lg[30];
int apar[MAXN];

int niv = 1, lim;

void parcurgere(int nod){
    nivel[nod] = niv;
    euler[++lim] = nod;
    for(auto x:graf[nod]){
        niv++;
        parcurgere(x);
        niv--;
        euler[++lim] = nod;
    }
}

int main()
{
    ifstream fin("lca.in");
    ofstream fout("lca.out");
    int n, m;
    fin >> n >> m;
    for(int i = 2; i <= n; ++i){
        fin >> tata[i];
        graf[tata[i]].push_back(i);
        lg[i] = lg[i / 2] + 1;
    }
    parcurgere(1);
    for(int i = 1; i < lim; ++i) rmq[0][i] = euler[i];
    for(int i = 1; (1 << i) <= lim; ++i){
        for(int j = 1; j <= lim - (1 << i) + 1; ++j){
            if(nivel[rmq[i - 1][j]] < nivel[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))];
        }
    }
    for(int i = 1; i <= n; ++i){
        for(int j = 1; j <= lim; ++j){
            if(euler[j] == i && apar[i] == 0){
                apar[i] = j;
                continue;
            }
        }
    }
    while(m){
        int x, y;
        fin >> x >> y;
        x = apar[x];
        y = apar[y];
        int logdif = lg[abs(x - y)];
        fout << min(rmq[logdif][x], rmq[logdif][y - (1 << logdif) + 1]) << "\n";
        m--;
    }
    return 0;
}