#include <bits/stdc++.h>

using namespace std;

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

const int MAXN = 1e5;
const int MAXM = 2e6;
const int MAXLOG = 15;

int n, m;
vector<int> g[MAXN + 1], euler;
int prim[MAXN + 1], grad[MAXN + 1];
bool viz[MAXN + 1];

void dfs_euler(int nod) {
	viz[nod] = 1;
	euler.push_back(nod);
	prim[nod] = euler.size() - 1;
	for (auto x : g[nod]) {
		if (!viz[x]) {
			dfs_euler(x);
			euler.push_back(nod);
		}
	}
}

int query(int st, int dr) {

}


int main() {
	in >> n >> m;
	grad[1] = 1;
	euler.push_back(0);
	for (int i = 2; i <= n; ++ i) {
		int tata;
		in >> tata;
		g[tata].push_back(i);
		grad[i] = grad[tata] + 1;
	}
	dfs_euler(1);
	int rmq[MAXLOG][euler.size()];
	for (int i = 1; i < euler.size(); ++ i)
		rmq[0][i] = euler[i];

	for (int i = 1; 1 << i <= euler.size() - 1; ++ i) {
		for (int j = 1; j + (1 << i) <= euler.size(); ++ j) {
			if (grad[rmq[i - 1][j]] < grad[rmq[i - 1][j + (1 << (i - 1))]])
				rmq[i][j] = rmq[i - 1][j];
			else
				rmq[i][j] = rmq[i - 1][j + (1 << (i - 1))];
		}
	}

	int a, b, st, dr;
	for (int i = 1; i <= m; ++ i) {
		in >> a >> b;
		st = min(prim[a], prim[b]);
		dr = max(prim[a], prim[b]);
			int l = dr - st + 1;
	int log = 31 - __builtin_clz(l);
	if (grad[rmq[log][st]] < grad[rmq[log][dr - (1 << log) + 1]])
		out << rmq[log][st] << '\n';
	else
		out << rmq[log][dr - (1 << log) + 1] << '\n';
	}

	return 0;
}