#include <fstream>
#include <vector>
#include <cmath>

using namespace std;

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

int n, m, timer,l;
vector<vector<int>> adj,up;
vector<int>tin, tout;

void dfs(int v, int p)
{
	tin[v] = ++timer;
	up[v][0] = p;
	for (int i = 1; i <= l; ++i)
		up[v][i] = up[up[v][i - 1]][i - 1];
	for (int u : adj[v])
		if (u != p)
			dfs(u, v);
	tout[v] = ++timer;
}

bool is_ancestor(int u, int v)
{
	return tin[u] <= tin[v] && tout[u] >= tout[v];
}

int lca(int u, int v)
{
	if (is_ancestor(u, v))
		return u;
	if (is_ancestor(v, u))
		return v;
	for (int i = l; i >= 0; --i)
		if (!is_ancestor(up[u][i], v))
			u = up[u][i];
	return up[u][0];
}

void preprocess()
{
	timer = 0;
	dfs(1, 1);
}

int main()
{
	in >> n >> m;
	l = ceil(log2(n));
	adj.resize(n + 1);
	tin.resize(n + 1);
	tout.resize(n + 1);
	up.assign(n + 1, vector<int>(l + 1));
	for (int i = 2; i <= n; ++i)
	{
		int a;
		in >> a;
		adj[a].push_back(i);
		adj[i].push_back(a);
	}
	preprocess();
	for (int i = 0; i < m; ++i)
	{
		int a, b;
		in >> a >> b;
		out << lca(a, b) << "\n";
	}
    return 0;
}