#include <fstream>
#include <algorithm>
using namespace std;

ifstream fin("lca.in");
ofstream fout("lca.out");
#define dim 100005
#define logn 20
int stramos[dim][logn], t[dim];
int n, m, i;

inline bool cmp(int a , int b)
{
	return a>b;
}

void read()
{
	fin>> n >>m;
	for(i=2;i<=n;++i)
	{
		int par,grad=0;
		fin>>par;
		t[i]=par;
		while(par!=0)
		{
			++grad;
			stramos[i][grad]=par;
			par=t[par];
		}
		stramos[i][++grad]=i;
		stramos[i][0]=grad;
	}
	
	for(i=2;i<=n;++i)
		sort(stramos[i]+1,stramos[i]+20,cmp);
	
}

void solve()
{
	int a, b;
	stramos[1][0]=1;
	stramos[1][1]=1;
	for(i=1;i<=m;++i)
	{
		fin>>a >>b;
		int ok=1,j,k;
		
		for(j=1;;++j)
		{
			for(k=1;k<=stramos[b][0];++k)
				if(stramos[a][j]==stramos[b][k])
				{ok=0;break;}
				if(ok==0)
					break;
		}
		fout<<stramos[a][j] <<'\n';
	}
		
	
}

int main()
{
	read();
	solve();
	return 0;
}