#include <bits/stdc++.h>

using namespace std;

const int N = (int) 2e5 + 7;
const int K = 19;
int n;
int p[N];
int dep[N];
int euler_tour[2 * N];
int tour_sz;
int first_time_on_tour[N];
int last_time_on_tour[N];
int lg2[2 * N];
vector<int> g[N];
pair<int, int> tab_lca[2 * N][K];

void dfs_lca(int a)
{
    euler_tour[++tour_sz] = a;
    first_time_on_tour[a] = last_time_on_tour[a] = tour_sz;
    for (auto &b : g[a])
    {
        dep[b] = 1 + dep[a];
        dfs_lca(b);
        euler_tour[++tour_sz] = a;
        last_time_on_tour[a] = tour_sz;
    }
}

void lcaTM()
{
    dfs_lca(1);
    for (int i = 2; i <= tour_sz; i++)
    {
        lg2[i] = 1 + lg2[i / 2];
    }
    for (int i = 1; i <= tour_sz; i++)
    {
        tab_lca[i][0] = {dep[euler_tour[i]], euler_tour[i]};
    }
    for (int k = 1; (1 << k) <= tour_sz; k++)
    {
        for (int i = 1; i + (1 << k) - 1 <= tour_sz; i++)
        {
            tab_lca[i][k] = min(tab_lca[i][k - 1], tab_lca[i + (1 << (k - 1))][k - 1]);
        }
    }
}

int lca(int a, int b)
{
    if (first_time_on_tour[a] > last_time_on_tour[b])
    {
        swap(a, b);
    }
    a = first_time_on_tour[a];
    b = last_time_on_tour[b];
    int k = lg2[b - a + 1];
    return min(tab_lca[a][k], tab_lca[b - (1 << k) + 1][k]).second;
}

int main()
{
    ios::sync_with_stdio(0);
    cin.tie(0);
    freopen ("lca.in", "r", stdin);
    freopen ("lca.out", "w", stdout);
    cin >> n; int q; cin >> q;
    for (int i = 2; i <= n; i++)
    {
        cin>> p[i];
        g[p[i]].push_back(i);
    }
    lcaTM();
    while (q--)
    {
        int a, b;
        cin >> a >> b;
        cout << lca(a, b) << "\n";
    }
}
/// to do : compute Lowest common ancestor