#include <bits/stdc++.h>
using namespace std;

#define pb push_back
#define dbg(x) cout << #x <<": " << x << "\n";
#define sz(x) ((int)x.size())

using ll = long long;

const string fn = "lca";
ifstream fin(fn + ".in");
ofstream fout(fn + ".out");

int n, q;
vector<int> g[200005];

int rmq[20][200005];
int logs[200005];
int lvl[200005];
int euler[200005];
int poz[200005];
int k;
void dfs(int nod, int niv) {

	euler[++k] = nod;
	lvl[k] = niv;
	poz[nod] = k;
	for (int i : g[nod]) {
		dfs(i, niv + 1);
		euler[++k] = nod;
		lvl[k] = niv;
	}

}


int main() {
	int x;
	fin >> n >> q;
	for (int i = 2; i <= n; i++)
	{
		fin >> x;
		g[x].push_back(i);
	}
	dfs(1, 0);

	for (int i = 2; i <= k; ++i)
		logs[i] = logs[i / 2] + 1;

	for (int i = 1; i <= k; ++i)
		rmq[0][i] = i;
	for (int i = 1; (1 << i) <= k; ++i)
		for (int j = 1; j + (1 << i) - 1 <= k; ++j) {
			int logac = j + (1 << (i - 1));
			rmq[i][j] = rmq[i - 1][j];
			if (lvl[rmq[i - 1][logac]] < lvl[rmq[i - 1][j]])
				rmq[i][j] = rmq[i - 1][logac];
		}

	while (q--) {
		int x, y;
		fin >> x >> y;
		x = poz[x];
		y = poz[y];
		if (x > y)
			swap(x, y);
		int logac = logs[y - x + 1];
		int ans = rmq[logac][x];
		if (lvl[ans] < lvl[rmq[logac][y - (1 << logac) + 1]])
			ans = rmq[logac][y  - (1 << logac) + 1];
		fout << euler[ans] << '\n';
	}

	return 0;
}