#include <vector>
#include <fstream>
#define MAX_N 100005
#define MAX_L 20
#define foreach(V) for(typeof (V).begin() it = (V).begin(); it != (V).end(); ++it)
using namespace std;
int K, N, M,L[MAX_N << 1], H[MAX_N << 1],Lg[MAX_N << 1], First[MAX_N],Rmq[MAX_L][MAX_N << 2];
vector <int> G[MAX_N];
ifstream fin ("lca.in");
ofstream fout ("lca.out");
void dfs(int nod, int lev)
{
	H[++K] = nod; 
	L[K] = lev; 
	First[nod] = K; 
	foreach(G[nod])
	{
		dfs(*it, lev+1);
		H[++K] = nod;
		L[K] = lev;
	}
}
int main()
{
	fin >> N >> M;
	for(int i = 2; i <= N; ++i)
	{
		int x;
		fin >> x;
		G[x].push_back(i);
	}
	dfs(1, 0);
	for(int i = 2; i <= K; ++i) Lg[i] = Lg[i >> 1] + 1;
	for(int i = 1; i <= K; ++i) Rmq[0][i] = i;
	for(int i = 1; (1 << i) < K; ++i)
		for(int j = 1; j <= K - (1 << i); ++j)
		{
			int l = 1 << (i - 1);
			Rmq[i][j] = Rmq[i-1][j];
			if(L[Rmq[i-1][j + l]] < L[Rmq[i][j]]) Rmq[i][j] = Rmq[i-1][j + l];
		}
	while(M--)
	{
		int x, y;
		fin >> x >> y;
		int diff, l, sol, sh;
		int a = First[x], b = First[y];
		if(a > b) swap(a, b);
		diff = b - a + 1;
		l = Lg[diff];
		sol = Rmq[l][a];
		sh = diff - (1 << l);
		if(L[sol] > L[Rmq[l][a + sh]]) sol = Rmq[l][a + sh];
		fout<<H[sol]<<"\n";
	}
}