#include<cstdio>
#include<vector>
#include<cmath>

#define Vmax 300001
#define Nmax 100001
#define logV 20
using namespace std;

int N,M,m[logV][Vmax],poz[Vmax];

vector <pair <int,int> > v;
vector <int> a[Nmax];

void dfs(int nod,int depth){
	
	v.push_back(make_pair(nod,depth));
	poz[nod]=v.size();
	
	for(vector<int>::iterator it = a[nod].begin(); it!=a[nod].end(); ++it){
		
		dfs(*it,depth+1);
		v.push_back(make_pair(nod,depth));
		
	}
	
}

void rmq(){
	
	int Z=v.size();
	
	for(int i=0;i<Z;++i)
		m[0][i+1]=i;
	
	for(int lung=1; 1<<lung <=Z; ++lung)
		for(int start=1; start+( 1 << (lung-1) ) <=Z ; ++start)
			
			if(v[m[lung-1][start]].second <= v[m[lung-1][start + (1<< (lung-1))]].second )
				m[lung][start] =  m[lung-1][start];
			
			else m[lung][start] = m[lung-1][start + (1<< (lung-1))];
}
int main(){

	//freopen("lca.in","r",stdin);
	//freopen("lca.out","w",stdout);
	
	scanf("%d%d",&N,&M);
	
	for(int i=1;i<N;++i){
		int x;
		scanf("%d",&x);
		a[x].push_back(i+1);
	}
	
	dfs(1,1);
	rmq();
	
	for(int i=1;i<=M;++i){
		
		int x,y;
		
		scanf("%d%d",&x,&y);
		
		x=poz[x];
		y=poz[y];
		if(x>y) swap(x,y);
		int lgl  =(int)log2(y-x+1);
		
		if( v[m[lgl][x]].second < v[m[lgl][y - (1<<lgl)+1]].second )
			printf("%d\n",m[lgl][x]);
		else printf("%d\n",m[lgl][y - (1<<lgl)+1]);		
	}
	
	
return 0;
}