#include<stdio.h>
#include<vector>
using namespace std;
FILE*f=fopen("lca.in","r");
FILE*g=fopen("lca.out","w");
int n,m,w[200005],nr1,nr,lvl[100001],t[100001],pr[100001],x,y,pp[200001],p[200001];
vector <int> v[100001];
void dfs(int nod,int niv)
{
	lvl[nod]=niv;
	w[++nr]=nod;
	pr[nod]=nr;
	for(int i=0;i<v[nod].size();++i)
	{
		dfs(v[nod][i],niv+1);
		w[++nr]=nod;
	}
	
}
struct rmq
{
	int x,y;
} a[400001][20];
rmq min(rmq a,rmq b)
{
	if(a.x<b.x)
		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>>1]+1;
	pp[0]=1;
	for(int i=1;i<=18;++i)
		pp[i]=pp[i-1]<<1;
	
	
	for(int i=1;i<=nr;++i)
	{
		a[i][0].x=lvl[w[i]];
		a[i][0].y=w[i];
	}
	for(int j=1;j<=p[nr];++j)
		for(int i=1;i<=nr;++i)
			a[i][j]=min(a[i][j-1],a[i+pp[j-1]][j-1]);
		
		
		
	for(int i=1;i<=m;++i)
	{
		fscanf(f,"%d%d",&x,&y);
		x=pr[x];
		y=pr[y];
		if(x>y)
		{
			int aux=x;
			x=y;
			y=aux;
		}
		fprintf(g,"%d\n",min(a[x][p[y-x+1]],a[y-pp[p[y-x+1]]+1][p[y-x+1]]).y);
	}		
	
	fclose(g);
	fclose(f);
	return 0;
}