#include <fstream>
using namespace std;

const int Nmax = 100005;

int rmq[17][Nmax];
int level[Nmax];
int n, m;

int go_up(int nod, int steps)
{
    for(int i = 16; i>=0; i--)
        if((1 << i) <= steps)
        {
            nod = rmq[i][nod];
            steps -= (1<<i);
        }
        return nod;
}

int find_level(int nod)
{
    if(level[nod])
        return level[nod];

    level[nod] = 1 + find_level(rmq[0][nod]);
    return level[nod];
}

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

    cin >> n >> m;

    for(int i = 2; i<=n; i++)
    {
        cin >> rmq[0][i];
    }

    level[1] = 1;
    for(int i = 2; i <= n; i++)
        level[i] = find_level(i);

    for(int i = 1; i < 17; i++)
        for(int nod = 1; nod <= n; nod++)
            rmq[i][nod] = rmq[i-1][rmq[i-1][nod]];

    while(m--)
    {
        int x, y;
        cin >> x >> y;
        if(level[y] < level[x])
        {
            swap(x, y);
        }

        y = go_up(y, level[y] - level[x]);
        if(x == y)
        {
            cout << x << '\n';
            continue;
        }

        for(int i = 16; i>=0; i--)
            if(rmq[i][x] != rmq[i][y])
            {
                x = rmq[i][x];
                y = rmq[i][y];
            }
            cout << rmq[0][x] << '\n';
    }
}