#include <fstream>
#include <vector>
#include <iostream>
#define DIM 100002

using namespace std;

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

int n, Q, x, y, eulerSize;
int father[DIM], pow2[4 * DIM];

pair<int, int> appeared[DIM];

pair<int, int> rmq[25][4 * DIM], euler[4 * DIM];

bool viz[DIM];

vector<int> arb[DIM];

void dfs(int nod, int level)
{
	viz[nod] = 1;
	euler[++eulerSize] = { level, nod };
	appeared[nod].first = eulerSize;

	for (auto nextNode : arb[nod])
	{
		if (viz[nextNode])
			continue;
		dfs(nextNode, level + 1);
		euler[++eulerSize] = { level, nod };
		appeared[nod].second = eulerSize;
	}

	if (appeared[nod].second == 0)
	{
		euler[++eulerSize] = { level, nod };
		appeared[nod].second = eulerSize;
	}
}

int main(int argc, const char * argv[])
{

	in >> n >> Q;

	for (int i = 2; i <= n; ++i)
	{
		in >> x;
		arb[i].push_back(x);
		arb[x].push_back(i);
	}

	dfs(1, 1);

	pow2[1] = 0;
	for (int i = 2; i <= eulerSize; ++i)
		pow2[i] = 1 + pow2[i / 2];

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


	for (int i = 1; (1 << i) <= eulerSize; ++i)
	{
		for (int j = 1; j <= eulerSize; ++j)
		{
			if (j + (1 << (i - 1)) <= eulerSize)
				rmq[i][j] = min(rmq[i - 1][j], rmq[i - 1][j + (1 << (i - 1))]);
			else
				rmq[i][j] = rmq[i - 1][j];

		}
	}

	while (Q--)
	{
		in >> x >> y;
		int left = min(appeared[x].first, appeared[y].first);
		int right = max(appeared[x].second, appeared[y].second);

		int pow = pow2[right - left + 1];

		pair<int, int> minim = min(rmq[pow][left], rmq[pow][right - (1 << pow) + 1]);

		out << minim.second << '\n';

	}



	return 0;
}