#include <iostream>
#include <fstream>
#include <vector>
using namespace std;
ifstream fin("lca.in");
ofstream fout("lca.out");
#define MAX 100010
typedef vector <int> :: iterator iter;
vector <int> G[MAX];
int depth[MAX], dr, dad[MAX], st[20][2 * MAX], poz[MAX], lg[2 * MAX];
void df(int nod)
{
    depth[nod] = depth[dad[nod]] + 1;
    st[0][++dr] = nod;
    poz[nod] = dr;
    for(iter it = G[nod].begin() ; it != G[nod].end() ; it++)
    {
        df(*it);
        st[0][++dr] = nod;
    }
}

int main()
{
    int q, i, n, j, x, y;
    fin >> n >> q;
    lg[0] = -1;
    for(i = 2 ; i <= n ; i++)
    {
        fin >> dad[i];
        G[dad[i]].push_back(i);
    }
    df(1);
    for(i = 1 ; i <= dr ; i ++)
    {
        lg[i] = lg[i / 2] + 1;
  //      cout << st[0][i] << " ";
    }
//    cout << "\n";
    for(j = 1 ; (1 << j) <= dr ; j++)
    {
        for(i = 1 ; i + (1 << j) - 1 <= dr ; i++)
        {
            if(depth[st[j - 1][i]] < depth[st[j - 1][i + (1<<(j - 1))]])
                st[j][i] = st[j - 1][i];
            else
                st[j][i] = st[j - 1][i + (1 << (j - 1))];
        }
    }
    while(q--)
    {
        fin >> x >> y;
        x = poz[x];
        y = poz[y];
        if(y < x)
            swap(x, y);
        int dist = y - x + 1;
        dist = lg[dist];
        if(depth[st[dist][x]] < depth[st[dist][y - (1 << dist) + 1]])
            fout << st[dist][x] << "\n";
        else
            fout << st[dist][y - (1 << dist) + 1] << "\n";
    }
}