#include<stdio.h>
#include<vector>
#define Nmax 100010
using namespace std;

int M[Nmax<<1][25],E[Nmax<<1],H[Nmax<<1],i,j,x,y,n,m,k,poz[Nmax],aux;
vector<int> V[Nmax];

void dfs(int nod,int h)
{
	E[++k]=nod;
	H[k]=h;
	poz[nod]=k;
	
	int N=V[nod].size(),t;
	
	for(t=0;t<N;t++)
	{
		dfs(V[nod][t],h+1);
		E[++k]=nod;
		H[k]=h;
	}
}	


void rmq()
{
	int j,i,N=(n<<1)-1;
	
	for(i=1;i<=N;i++)
		M[i][0]=i;
	
	for(j=1; (1<<j) <= N ; j++)
		for(i=1; i + (1<<j) -1 <= N; i++)
			if(H[M[i][j-1]] <= H[M[i+(1<<(j-1))][j-1]])
				M[i][j]=M[i][j-1];
			else M[i][j]=M[i+(1<<(j-1))][j-1];
}

int lca(int i, int j)
{
	int k=0,val=j-i+1,p;
	
	while(val!=1)
	{
		k++;
		val>>=1;
	}
	
	if( H[M[i][k]] <= H[M[j-(1<<k)+1][k]] )
		p=M[i][k];
	else p=M[j-(1<<k)+1][k];
	
	return E[p];
}

int main()
{
	
	freopen("lca.in","r",stdin);
	freopen("lca.out","w",stdout);
	
	scanf("%d %d",&n,&m);
	
	for(i=2;i<=n;i++)
	{
		scanf("%d",&x);
		V[x].push_back(i);
	}
	
	dfs(1,0);
	rmq();
	for(i=1;i<=m;i++)
	{
		scanf("%d %d",&x, &y);
		
		x=poz[x];
		y=poz[y];
		
		if(x>y) {aux=x; x=y; y=aux;}
		
		printf("%d\n",lca(x,y));
		
	}
	return 0;
}