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

#define pb push_back

#define dbg(x) cout << #x <<": " << x << "\n";
using ll = long long;

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

const int mxn = 200000;

int n, q;
int eulerTour[mxn + 5], lvl[mxn + 5], eulerSize;

int pozInTour[mxn / 2 + 5];
vector<int> g[mxn / 2 + 5];

void dfs(int nod, int niv) {
	eulerTour[++eulerSize] = nod;
	lvl[eulerSize] = niv;
	pozInTour[nod] = eulerSize;

	for (auto i : g[nod]) {
		dfs(i, niv + 1);
		eulerTour[++eulerSize] = nod;
		lvl[eulerSize] = niv;
	}
}

int logs[mxn + 5];
int rmq[20][mxn + 5];

void rmqq() {

	logs[1] = 0;
	for (int i = 2; i <= eulerSize; ++i)
		logs[i] = logs[i / 2] + 1;

	for (int i = 1; i <= eulerSize; ++i)
		rmq[0][i] = i;

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


}


int main() {

	fin >> n >> q;
	for (int i = 2 ; i <= n; ++i) {
		int x;
		fin >> x;
		g[x].pb(i);
	}

	dfs(1, 0);

	rmqq();

	while (q--) {
		int x, y;
		fin >> x >> y;
		x = pozInTour[x];
		y = pozInTour[y];
		int k = logs[y - x + 1];
		int ans = 0;
		if (lvl[rmq[k][x]] < lvl[rmq[k][y - (1 << k) + 1]])
			ans = rmq[k][x];
		else ans = rmq[k][y - (1 << k) + 1];
		fout << eulerTour[ans] << '\n';
	}

	return 0;
}