#include<fstream>
#include<iostream>
#include<math.h>
#include<vector>
using namespace std;
#define pb push_back
int euclid[500001];
int niv[500001];
vector<int> fiu[100001];
int first[500001];
int ct=0;
int n,m;
void euler(int k,int nivel){
	if(first[k]==0){
		first[k]=ct+1;
	}
	if(fiu[k].size()==0){
		ct++;
		euclid[ct]=k;
		niv[ct]=nivel;
	}
	else{
		
		int i;
		for(i=0;i<fiu[k].size();i++){
			ct++;
			euclid[ct]=k;
			niv[ct]=nivel;
			euler(fiu[k][i],nivel+1);
		}
		ct++;
		euclid[ct]=k;
		niv[ct]=nivel;
	}
}
int rmq[30][500000];
int nivelrmq[30][500000];
int lg[500000];
void rmqinit(){
	lg[1]=0;
	int i,j,l;
	for (i=2;i<=ct;i++)
		lg[i]=lg[i/2]+1;
	for (i=1;i<=ct;i++)
		rmq[0][i]=i;
	for (i=1; (1 << i) <ct;i++)
		for (j=1;j <= ct - (1 << i)+1;j++)
		{
			l=1<<(i-1);
			
			if(niv[rmq[i-1][j]]<=niv[rmq[i-1][j+1]])
				rmq[i][j]=rmq[i-1][j];
			else
				rmq[i][j]=rmq[i-1][j+1];
			
			
		}
}
int lca(int x,int y){
	int diff,l,sol,sh;
	int a=first[x];
	int 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(niv[sol]>niv[rmq[l][a + sh]])
		sol=rmq[l][a + sh];
	//cout<<x<<" "<<y<<" "<<first[x]<<" "<<first[y]<<"\n";
	return euclid[sol];
}	

int main(){
	ifstream f("lca.in");
	ofstream g("lca.out");
	f>>n>>m;
	int i,j;
	for(i=1;i<n;i++){
		f>>j;
		if(i+1>n){}
		else
		fiu[j].pb(i+1);
	}
	euler(1,0);
	/*for(i=1;i<=ct;i++){
		cout<<euclid[i]<<" ";
	}
	*/
	rmqinit();
	for(i=1;i<=m;i++){
		int a,b;
		f>>a>>b;
		g<<lca(a,b)<<"\n";
	}
	
	return 0;
}