#include <iostream>
#include <fstream>
#include <vector>
#include <stack>
#include <bitset>
#include <algorithm>
#define NMAX 100003
#define LMAX 19

using namespace std;
ifstream in("lca.in");
ofstream out("lca.out");
vector <int> G[NMAX];
stack <int> st;
bitset <NMAX> mark;
int N, M;
int height[NMAX], euler_n[2 * NMAX], euler_h[2 * NMAX];
int pos[NMAX], lg[2 * NMAX];
int sp[LMAX][NMAX];

void dfs()
{
	st.push(1);
	mark.set(1);
	int top, node, ok;
	while (!st.empty())
	{
		top = st.top();
		ok = 0;
		euler_n[++euler_n[0]] = top;
		for (unsigned int i = 0; i < G[top].size(); i++)
			if (!mark.test(G[top][i]))
			{
				node = G[top][i];
				ok = 1;
				break;
			}
		if (ok)
		{
			st.push(node);
			mark.set(node);
			height[node] = height[top] + 1;
		}
		else
			st.pop();
	}
}

void sparse_table()
{
	int dim = euler_n[0];
	for (int i = 2; i <= dim; i++)
		lg[i] = lg[i / 2] + 1;
	for (int i = 1; i <= dim; i++)
		sp[0][i] = i;
	for (int i = 1; (1 << i) <= dim; i++)
		for (int j = 1; j + (1 << i) - 1 <= dim; j++)
			if (euler_h[sp[i - 1][j]] <= euler_h[sp[i - 1][j + (1 << (i - 1))]])
				sp[i][j] = sp[i - 1][j];
			else
				sp[i][j] = sp[i - 1][j + (1 << (i - 1))];
}

int main()
{
	in >> N >> M;
	int x, y;
	for (int i = 2; i <= N; i++)
	{
		in >> x;
		G[x].push_back(i);
	}
	dfs();
	euler_h[0] = euler_n[0];
	for (int i = 1; i <= euler_n[0]; i++)
	{
		euler_h[i] = height[euler_n[i]];
		if (pos[euler_n[i]] == 0)
			pos[euler_n[i]] = i;
	}
	sparse_table();
	int k, lca;
	for (int i = 1; i <= M; i++)
	{
		in >> x >> y;
		x = pos[x];
		y = pos[y];
		if (x > y)
			swap(x, y);
		k = lg[y - x + 1];
		if (euler_h[sp[k][x]] <= euler_h[sp[k][y - (1 << k) + 1]])
			lca = euler_n[sp[k][x]];
		else
			lca = euler_n[sp[k][y - (1 << k) + 1]];
		out << lca << "\n";
	}
	in.close();
	out.close();
	return 0;
}