#include <iostream>
#include <fstream>
using namespace std;

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

/*

const int L = 18;
int n, m, nr, timp, vf[100001], urm[100001], lst[100001], t[L][100001], tb[100001], to[100001];

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

void dfs(int x) {
	tb[x] = ++timp;
	int y;
	for (int p = lst[x]; p != 0; p = urm[p]) {
		y = vf[p];
		if (tb[y] == 0) {
			dfs(y);
			t[0][y] = x;
		}
	}
	to[x] = ++timp;
}

int lca(int x, int y) {
	if (tb[x] <= tb[y] && to[y] <= to[x])
	{
		return x;
	}
	int pas = L - 1;
	int s;
	while (pas >= 0) {
		s = t[pas][x];
		if (s != 0 && ((tb[s] > tb[y]) || (to[s] < to[y]))) {
			x = s;
        }
		pas--;
	}
	return t[0][x];
}

int main() {
	in >> n >> m;
	for (int i = 2; i <= n; i++) {
		int a;
		in >> a;
		add(a, i);
	}
	dfs(1);
	for (int i = 1; (1 << i) <= n; i++){
		for (int j = 1; j <= n; j++){
			t[i][j] = t[i - 1][t[i - 1][j]];
        }
	}
	for (int i = 1; i <= m; i++) {
		int x, y;
		in >> x >> y;
		out << lca(x, y) << '\n';
	}
	return 0;
}
*/


const int N = 100001;
const int L = 18;

int n, m, nr, a, vf[N], urm[N], lst[N], rmq[L][2 * N], nivel[N], prima[N], rang[2 * N], log[2 * N];

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

void dfs(int x) {
	rang[++a] = x;
	prima[x] = a;
	int y;
	for (int p = lst[x]; p != 0; p = urm[p]) {
		y = vf[p];
		if (prima[y] == 0) {
			nivel[y] = 1 + nivel[x];
			dfs(y);
			rang[++a] = x;
		}
	}
}

int lca(int x, int y) {
	int p = prima[x];
	int q = prima[y];
	if (p > q){
            swap(p, q);
	}
	int l = log[q - p + 1];
	int st = rmq[l][p + (1 << l) - 1];
	int dr = rmq[l][q];
	int rez = st;
	if (nivel[rang[dr]] < nivel[rang[rez]]) {
            rez = dr;
	}
	return rang[rez];
}

int main() {
	in >> n >> m;
	for (int i = 2; i <= n; i++) {
		int a;
		in >> a;
		add(a, i);
	}
	log[1] = 0;
	for (int i = 2; i <= 2 * n; i++){
		log[i] = 1 + log[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 (nivel[rang[st]] <= nivel[rang[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;
}