#include <iostream>
#include <fstream>

using namespace std;

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

const int N = 100001;
const int L = 18;
int n, m, nr, ne, vf[N], urm[N], lst[N], rmq[L][2 * N], level[N], first[N], e[2 * N], logaritm[2 * N]; 
// matricea t va tine al 2-lea stramos al lui j, t[i][j]

void add(int x, int y) {
	vf[++nr] = y;
	urm[nr] = lst[x];
	lst[x] = nr;
}

void dfs(int x) {
	e[++ne] = x;
	first[x] = ne; // prima pozitie pe care apare fiecare nod
	int y;
	for (int p = lst[x]; p != 0; p = urm[p]) {
		y = vf[p];
		if (first[y] == 0) { // nu am mai fost pe acolo
			level[y] = 1 + level[x];
			dfs(y);
			e[++ne] = x;
			
		}
	}
}

int lca(int x, int y) {
	int p = first[x];
	int q = first[y];
	if (p > q) swap(p, q);
	int l = logaritm[q - p + 1];
	int st = rmq[l][p + (1 << l) - 1];
	int dr = rmq[l][q];
	int rez = st;
	if (level[e[dr]] < level[e[rez]]) rez = dr; // pozitia din euler
	return e[rez];
}

int main() {
	in >> n >> m;
	for (int i = 2; i <= n; i++) {
		int a;
		in >> a;
		add(a, i);
	}

	logaritm[1] = 0;
	for (int i = 2; i <= 2 * n; i++)
		logaritm[i] = 1 + logaritm[i / 2];

	dfs(1);
	for (int j = 1; j < 2 * n; j++) {
		rmq[0][j] = j;
	}
	for (int i = 1; (1 << i) < 2 * n; i++) {
		for (int j = 1 << i; j < 2 * n; j++) {
			int st = rmq[i - 1][j - (1 << (i - 1))];
			int dr = rmq[i - 1][j];
			if (level[e[st]] <= level[e[dr]]) rmq[i][j] = st;
			else rmq[i][j] = dr;
		}
	}

	for (int i = 1; i <= m; i++) {
		int x, y;
		in >> x >> y;
		out << lca(x, y) << '\n';
	}
	return 0;
}