#include<stdio.h>
#include<vector>
using namespace std;
FILE*f=fopen("lca.in","r");
FILE*g=fopen("lca.out","w");
int m,n,p[400001],w[400001],t[100001],poz[100001],nr,x,y,a[20][400001],lvl[100001];
vector <int> v[100001];
void dfs(int nod,int niv)
{
	w[++nr]=nod;
	if(!poz[nod])
	{
		poz[nod]=nr;
		lvl[nod]=niv;
	}
	for(int i=0;i<v[nod].size();++i)
	{
		dfs(v[nod][i],niv+1);
		w[++nr]=nod;
	}
	return ;
}
int min(int a,int b)
{
	if(lvl[a]<lvl[b])
		return a;
	return b;
	
}
int main()
{
	fscanf(f,"%d%d",&n,&m);
	for(int i=2;i<=n;++i)
	{
		fscanf(f,"%d",&t[i]);
		v[t[i]].push_back (i);
	}
	
	dfs(1,1);
	
	for(int i=2;i<=nr;++i)
		p[i]=p[i/2]+1;
	
	for(int i=1;i<=nr;++i)
		a[0][i]=w[i];
	
	for(int i=1;i<=p[nr];++i)
		for(int j=1;j<=nr-(1<<i)+1;++j)
			a[i][j]=min(a[i-1][j],a[i-1][j+(1<<(i-1))]);
	
	for(int i=1;i<=m;++i)
	{
		fscanf(f,"%d%d",&x,&y);
		x=poz[x];
		y=poz[y];
		if(x>y)
		{
			int aux=x;
			x=y;
			y=aux;
		}
		int L=y-x+1;
		int sol=min(a[p[L]][x],a[p[L]][y-(1<<p[L])+1]);
		fprintf(g,"%d\n",sol);
	}
	
	
	
	
	fclose(f);
	fclose(g);
	return 0;
}