#include <fstream>
#include <vector>
using namespace std;

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

const int NMAX = 100005;
const int KMAX = 20;

int n, m, deep[NMAX], euler[2 * NMAX], k, euler_lvl[2 * NMAX];

int rmq[KMAX][2 * NMAX], lg[2 * NMAX], fst[NMAX];

vector <int> g[NMAX];

void DFS(int node)
{
	euler[++k] = node;
	euler_lvl[k] = deep[node];
	fst[node] = k;
	for (auto i : g[node])
	{
		deep[i] = deep[node] + 1;
		DFS(i);
		euler[++k] = node;
		euler_lvl[k] = deep[node];
	}
}

void RMQ()
{
	rmq[0][1] = 1;
	for (int i = 2; i <= k; ++i)
	{
		rmq[0][i] = i;
		lg[i] = lg[i >> 1] + 1;
	}
	for (int i = 1; (1 << i) <= k; ++i)
		for (int j = 1; j + (1 << i) - 1 <= k; ++j)
		{
			int ind1 = rmq[i - 1][j], ind2 = rmq[i - 1][(j + (1 << (i - 1)))];
			if (euler_lvl[ind1] > euler_lvl[ind2])
				rmq[i][j] = ind2;
			else rmq[i][j] = ind1;
		}
}

int lca(int x, int y)
{
	x = fst[x];
	y = fst[y];
	if (x > y)
		swap(x, y);
	int t = lg[y - x + 1];
	int ind1 = rmq[t][x], ind2 = rmq[t][y - (1 << t) + 1];
	if (euler_lvl[ind1] < euler_lvl[ind2])
		return euler[ind1];
	return euler[ind2];
}

int main()
{
	int x, y;
	fin >> n >> m;
	for (int i = 2; i <= n; ++i)
	{
		fin >> x;
		g[x].push_back(i);
	}
	deep[1] = 1;
	DFS(1);
	RMQ();
	while (m--) 
	{
		fin >> x >> y;
		fout << lca(x, y) << "\n";
	}
	fout.close();
	return 0;
}