#include <iostream>
#include <fstream>
#include <vector>

using namespace std;
typedef vector<int>::iterator iter;

#define MAXN 100005

ifstream f("lca.in");
ofstream g("lca.out");

int n, m;
vector<int> G[MAXN];
vector< pair<int, int> > order;
int poz[MAXN], lvl[MAXN];

void euler(int nd = 1, int lv = 0)
{
    order.push_back(make_pair(nd, lv));
    for (iter it = G[nd].begin(); it != G[nd].end(); it++) {
        euler(*it, lv + 1);
        order.push_back(make_pair(nd, lv));
    }
}

int query(int st, int dr)
{
    int mn = order[st].second, rez = st;
    for (int i = st + 1; i <= dr; i++) {
        if (mn > order[i].second) {
            mn = order[i].second;
            rez = order[i].first;
        }
    }
    return rez;
}

int main()
{
    f >> n >> m;
    for (int i = 2; i <= n; i++) {
        int x;
        f >> x;
        G[x].push_back(i);
    }

    euler(1, 0);

    for (int i = order.size() - 1; i >= 0; i--) {
        poz[order[i].first] = i;
    }

    for (int i = 1; i <= m; i++) {
        int x, y;
        f >> x >> y;
        g << query(poz[x], poz[y]) << '\n';
    }

    f.close();
    g.close();
    return 0;
}