#include <iostream>
#include <fstream>
#include <vector>
#include <cmath>
#include <algorithm>
#include <string>
#include <bitset>
#include <stack>
#include <queue>
#include <deque>

using namespace std;

#ifdef LOCAL
ifstream fin("input.txt");
#define fout cout
#else
ifstream fin("lca.in");
ofstream fout("lca.out");
#endif

const int NMAX = 1e5+5;
const int LOGN = 18;

int n, m;
int a[NMAX];
int dp[NMAX][LOGN];
int x, y;
vector<int> tree[NMAX];
vector<int> e;
int lv[NMAX];
int pos[NMAX];
int cnt;

void dfs(int x, int l) {
	lv[x] = l;
	pos[x] = e.size();
	for (auto v : tree[x]) {
		//e.push_back(x);
		cnt++;
		dfs(v, l + 1);
	}
	cnt++;
	//e.push_back(x);
}

void precalc() {
	dfs(1, 0);
	for (int i = 0; i < e.size(); i++)
		dp[i][0] = i;
	for (int j = 1; (1 << j) <= e.size(); j++) {
		for (int i = 0; i + (1 << j) - 1 < e.size(); i++) {
			int p1 = dp[i][j - 1];
			int p2 = dp[i + (1 << (j - 1))][j - 1];
			dp[i][j] = lv[e[p1]] < lv[e[p2]] ? p1 : p2;
		}
	}
}

int query(int i, int j) {
	i = pos[i], j = pos[j];
	if (i > j)
		swap(i, j);
	int k = log2(j - i + 1);
	int p1 = e[dp[i][k]];
	int p2 = e[dp[j - (1 << k) + 1][k]];
	return lv[p1] < lv[p2] ? p1 : p2;
}

int main() {
	fin >> n >> m;
	int x;
	for (int i = 2; i <= n; i++) {
		fin >> x;
		tree[x].push_back(i);
	}
	precalc();
	return cnt / 10000;
	while (m--) {
		fin >> x >> y;
		fout << query(x, y) << '\n';
	}
	return 0;
}