#include <cassert>
#include <cstdio>
#include <deque>
#include <iostream>
#include <vector>

using namespace std;

inline int next_int() {
	int d;
	scanf("%d", &d);
	return d;
}

const int MAX = 18;

vector<int> G[100000];
vector<int> E, L, H;
int P[100000];
int ST[1 << MAX][MAX];
int LG[1 << MAX];

inline int lca(int a, int b) {
	if (H[a] > H[b]) {
		swap(a, b);
	}
	a = H[a], b = H[b] + 1;
	int k = LG[b - a];
	if (L[H[ST[a][k]]] < L[H[ST[b - (1 << k)][k]]]) {
		return ST[a][k];
	} else {
		return ST[b - (1 << k)][k];
	}
}

void dfs(int u, int depth) {
	E.push_back(u);
	L.push_back(depth);
	for (size_t i = 0; i < G[u].size(); i++) {
		dfs(G[u][i], depth + 1);
		E.push_back(u);
		L.push_back(depth);
	}
}

int main() {
	for (int i = 0; i < MAX - 1; i++) {
		for (int j = 1 << i; j < 2 << i; j++) {
			LG[j] = i;
		}
	}
	freopen("lca.in", "r", stdin);
	freopen("lca.out", "w", stdout);
	int n = next_int();
	int m = next_int();
	for (int i = 1; i < n; i++) {
		P[i] = next_int() - 1;
		G[P[i]].push_back(i);
	}
	dfs(0, 0);
	for (size_t i = 0; i < E.size(); i++) {
		ST[i][0] = E[i];
	}
	H.assign(n, -1);
	for (size_t i = 0; i < E.size(); i++) {
		H[E[i]] = H[E[i]] == -1 ? i : H[E[i]];
	}
	for (int j = 1; j < MAX; j++) {
		for (int i = 0; i + (1 << (j - 1)) < (1 << MAX); i++) {
			if (L[H[ST[i][j - 1]]] < L[H[ST[i + (1 << (j - 1))][j - 1]]]) {
				ST[i][j] = ST[i][j - 1];
			} else {
				ST[i][j] = ST[i + (1 << (j - 1))][j - 1];
			}
		}
	}
	for (int i = 0; i < m; i++) {
		int a = next_int() - 1;
		int b = next_int() - 1;
		printf("%d\n", lca(a, b) + 1);
	}
	return 0;
}