#include <bits/stdc++.h>

using namespace std;

#define MAX_N 100005
#define MAX_L 20


int K, N, M;
int L[MAX_N << 1], H[MAX_N << 1],Lg[MAX_N << 1], First[MAX_N];
int Rmq[MAX_L][MAX_N << 2];

vector <int> G[MAX_N];
void dfs(int nod, int lev)
{
	H[++K] = nod;
	L[K] = lev;
	First[nod] = K;

	for(vector<int>::iterator it = G[nod].begin(); it != G[nod].end(); ++it)
	{
		dfs(*it, lev+1);

		H[++K] = nod;
		L[K] = lev;
	}
}

void rmq()
{
	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];
		}
}

int lca(int x, int 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];
	return H[sol];
}

int main()
{
    freopen("lca.in","r",stdin);
    freopen("lca.out","w",stdout);
    scanf("%d %d",&N,&M);
	for(int i = 2; i <= N; ++i)
	{
		int x;
		scanf("%d",&x);
		G[x].push_back(i);
	}
	dfs(1, 0);
	rmq();

	while(M--)
	{
		int x, y;
		scanf("%d %d",&x,&y);
		printf("%d\n",lca(x,y));
	}
}