#include<fstream>
#include<iostream>
#include<vector>
using namespace std;
ifstream f("lca.in");
ofstream g("lca.out");
int K,N,M;
int L[100005<<1],H[100005<<1],Lg[100005<<1],First[100005];
int Rmq[20][10000<<2];
vector<int> G[100005];
void dfs(int nod, int lev)
{
	K++;
	H[K]=nod;///nodul actual este adaugat in reprezentarea Euler a arborelui
	L[K]=lev;///se retine nivelul fiecarei pozitii din reprezentarea Euler a arborelui
	First[nod]=K;///se retine si prima aparitie a fiecarui nod in reprezentarea Euler a arborelui
	vector<int>::iterator it;
	for(it=G[nod].begin();it!=G[nod].end();it++)
	{
		dfs(*it,lev+1);
		K++;
		H[K]=nod;
		L[K]=lev;
	}
}
void rmq()
{
    ///in Rmq[i][j] va fi nodul de nivel minim dintre pozitiile (j, j + 2^i - 1) din reprezentarea Euler a arborelui
	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)
{
    ///LCA-ul nodurilor x si y va fi nodul cu nivel minim din secventa (First[x], First[y]) din reprezentarea Euler a arborelui
	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()
{
	f>>N>>M;
	for(int i=2;i<=N;i++)
	{
		int x;
		f>>x;
		G[x].push_back(i);
	}
	dfs(1,0);
	/*for(i=1;i<=K;i++)
        cout<<H[i]<<" ";
    cout<<"\n";
    for(i=1;i<=K;i++)
        cout<<L[i]<<" ";*/
	rmq();
	while(M--)
	{
		int x,y;
		f>>x>>y;
		g<<lca(x,y)<<"\n";
	}
	f.close();
	g.close();
	return 0;
}