#include <iostream>
#include <fstream>
#include <vector>
using namespace std;
ifstream ka("lca.in");
ofstream ki("lca.out");

const int N_MAX = 100000;
const int LOG_MAX = 18;
vector< vector<int> >graf(N_MAX + 1);

int poz[N_MAX + 1], grad[N_MAX + 1];
int repr[2 * N_MAX + 1], log[2 * N_MAX + 1];
int minim[2 * N_MAX + 1][LOG_MAX];

int n, m, k;

void rep_euler(int t, int gr)
{
    repr[k] = t;
    if(!poz[t])
    {
        poz[t] = k;
        grad[t] = gr;
    }
    for(int i = 0; i < graf[t].size(); i++)
    {
        k++;
        rep_euler(graf[t][i], gr + 1);
        repr[k]= t;
    }
    k++;
}

int minul(int a, int b)
{
    if(grad[a] <= grad[b])
        return a;
    else
        return b;
}

int main()
{
    ka >> n >> m;
    int a;
    for(int i = 2; i <= n; i++)
    {
        ka >> a;
        graf[a].push_back(i);
    }
    rep_euler(1, 0);
    minim[1][0] = 1;
    for(int i = 2; i <= k; i++)
    {
        log[i] = log[i >> 1] + 1;
        minim[i][0] = repr[i];
    }
    for(int i = 1; i <= log[k]; i++)
    {
        for(int j = 1; j <= k - (1 << i); j++)
        {
            minim[j][i] = minul(minim[j][i-1], minim[j + (1 << (i-1))][i-1]);
        }
    }
    int x, y;
    for(int i = 1; i <= m; i++)
    {
        ka >> x >> y;
        x = poz[x];
        y = poz[y];
        if(x > y)
        {
            x += y;
            y = x -y;
            x -= y;
        }
        int dif = log[y - x];
        ki << minul(minim[x][dif], minim[y - (1 << dif) +1][dif]) << '\n';
    }
}