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

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

#define MAXN 100005
#define MAXL 18

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

int n, m, sz;
vector<int> G[MAXN];
vector< pair<int, int> > order;
int poz[MAXN], lvl[MAXN];
pair<int, int> dp[MAXL][2 * 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));
    }
}

void precompute()
{
    sz = order.size();
    for (int j = 1; j <= sz; j++) {
        dp[0][j] = order[j - 1];
    }
    for (int i = 1; (1 << i) <= sz; i++) {
        for (int j = 1; j + (1 << i) <= sz; j++) {
            dp[i][j] = min(dp[i - 1][j], dp[i - 1][j + (1 << (i - 1))]);
            if (dp[i - 1][j].second < dp[i - 1][j + (1 << (i - 1))].second) {
                dp[i][j] = dp[i - 1][j];
            } else {
                dp[i][j] = dp[i - 1][j + (1 << (i - 1))];
            }
        }
    }
}

int log(int nr)
{
    int rez = 1;
    while ((1 << rez) <= nr) rez++;
    return rez - 1;
}

int query(int st, int dr)
{
    int lg = log(dr - st + 1);
    pair<int, int> rez = dp[lg][dr - (1 << lg) + 1];
    if (dp[lg][st].second < rez.second) rez = dp[lg][st];
    return rez.first;
}

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

    euler(1, 0);
    precompute();

    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(min(poz[x], poz[y]) + 1, max(poz[x], poz[y]) + 1) << '\n';
    }

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