#include <bits/stdc++.h>
using namespace std;
 
const int MAXN = 200000 + 5;
 
int n, q, depth[MAXN], pos[MAXN], m;
int lg[2 * MAXN], rmq[20][2 * MAXN];
vector<int> euler, G[MAXN];
 
int minDepth(int x, int y) {
  return (depth[x] < depth[y] ? x : y);
}
 
void dsfEuler(int u, int dep = 0) {
  euler.emplace_back(u);
  depth[u] = dep + 1;
  pos[u] = (int)euler.size() - 1;
  for (const auto& v : G[u]) {
    dsfEuler(v, dep + 1);
    euler.emplace_back(u);
  }
}
 
void buildRmq() {  
  for(int i = 1; i <= m; i++) {
		rmq[0][i] = euler[i];
		if(i > 1)
			lg[i] = lg[i / 2] + 1;
	}
 
	for(int i = 1; i <= lg[m]; i++)
		for(int j = 1; j + (1 << (i - 1)) <= m; j++)
			rmq[i][j] = minDepth(rmq[i - 1][j], rmq[i - 1][j + (1 << (i - 1))]);
}
 
int LCA(int x, int y) {
	x = pos[x], y = pos[y];
	int k = lg[y - x + 1];
	return minDepth(rmq[k][x], rmq[k][y - (1 << k) + 1]);
}
 
int main() {
	ifstream cin("lca.in");
	ofstream cout("lca.out");
	
	int x, y;
  cin >> n >> q;
  for (int i = 2; i <= n; ++i) {
    cin >> x;
    G[x].emplace_back(i);
  }
 
  dsfEuler(1);
  m = euler.size() - 1;
  buildRmq();
 
  while(q--) {
    cin >> x >> y;
    cout << LCA(x, y) << '\n';
  }
 
  return 0;
}