#include <bits/stdc++.h>
using namespace std;

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

const int MAXN = 200000 + 5;

int n, nr, q, depth[MAXN], pos[MAXN];
int lg[2 * MAXN], rmq[20][2 * MAXN];
int euler[MAXN * 2];
vector<int> G[MAXN];
 
int minDepth(int x, int y) {
  return (depth[x] < depth[y] ? x : y);
}
 
void dsfEuler(int node, int dep = 0) {
  euler[++nr] = node;
  depth[node] = dep + 1;
  pos[node] = nr;
  
  for(int son : G[node]) {
    dsfEuler(son, dep + 1);
    euler[++nr] = node;
  }
}
 
void buildRMQ() {  
  for(int i = 1; i <= nr; i++) {
		rmq[0][i] = euler[i];
		if(i > 1)
			lg[i] = lg[i / 2] + 1;
	}
	
	for(int i = 1; i <= lg[nr]; i++)
		for(int j = 1; j + (1 << (i - 1)) <= nr; 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() {
	int x, y;
  fin >> n >> q;
  for(int i = 2; i <= n; ++i) {
    fin >> x;
    G[x].emplace_back(i);
  }
  
  dsfEuler(1);
  buildRMQ();
  
  while(q--) {
    fin >> x >> y;
    fout << LCA(x, y) << '\n';
  }
  
  return 0;
}