#include <bits/stdc++.h>
#define pii pair<int, int>
#define ff first
#define ss second
#define vi vector<int>
#define vvi vector<vi>
#define pb push_back
#define FOR(i, a, b) for(int i = a; i <= b; ++i)
#define FORR(i, a, b) for(int i = a; i >= b; --i)

using namespace std;
const string TASK("lca");
ifstream fin(TASK + ".in");
ofstream fout(TASK + ".out");
#define cin fin
#define cout fout

const int N = 1e5 + 9, LG = 21;

int n, q;
vvi G(N);

int ST[2 * N][LG], dep[N], first[N], tour[2 * N], idx;
void Dfs(int x = 1, int p = 0)
{
    dep[x] = dep[p] + 1;

    first[x] = ++ idx;
    tour[idx] = x;

    for(auto y : G[x])
    {
        if(y == p)continue;

        Dfs(y, x);
        tour[++ idx] = x;
    }
}
void Precalc()
{
    Dfs();

    FOR(i, 1, 2 * n)ST[i][0] = tour[i];

    for(int k = 1; (1 << k) <= 2 * n; ++k)
        for(int i = 1; i + (1 << k) - 1 <= 2 * n; ++i)
        {
            ST[i][k] = ST[i][k - 1];
            if(dep[ST[i][k - 1]] > dep[ST[i + (1 << (k - 1))][k - 1]])
                ST[i][k] = ST[i + (1 << (k - 1))][k - 1];
        }
}
int get_lca(int x, int y)
{
    x = first[x], y = first[y];
    if(x > y)swap(x, y);
    int k = log2(y - x + 1);
    return dep[ST[x][k]] < dep[ST[y - (1 << k) + 1][k]] ?
    ST[x][k] :
    ST[y - (1 << k) + 1][k];
}

int main()
{
    ios_base::sync_with_stdio(0), cin.tie(0), cout.tie(0);

    cin >> n >> q;

    int x, y;
    FOR(i, 2, n)
    {
        cin >> x;
        G[x].pb(i);
        G[i].pb(x);
    }

    Precalc();

    FOR(i, 1, q)
    {
        cin >> x >> y;
        cout << get_lca(x, y) << '\n';
    }
    return 0;
}