#include <iostream>
#pragma comment(linker,"/STACK:4000000")
#include <stdio.h>
#include <string>
#include <algorithm>
using namespace std;
int main()
{
		freopen("input.txt","rt",stdin);
	freopen("output.txt","wt",stdout);
	//cout.setf(ios::fixed | ios::showpoint);
	//cout.precision(2);
	long n,n1,n2,i,j,k;
    long double s,s1;
	cin>>n>>n1>>n2;
	cin>>s>>s1;
	s+=s1;
	long x[1000],y[1000];
	int mass[1000][1000];
	for(i=0;i<n;i++)cin>>x[i]>>y[i];
	for(i=0;i<n;i++)
	{
		for(j=0;j<n;j++)
		{
			if(i!=j&&((x[i]-x[j])*(x[i]-x[j])+(y[i]-y[j])*(y[i]-y[j]))<=s*s)mass[i][j]=mass[j][i]=1;
			else mass[i][j]=mass[j][i]=0;
		}
	}
	for(i=0;i<n;i++)y[i]=-1;
	long st=0,en=1;
	x[0]=n1-1;
	y[n1-1]=0;
	while(st!=en)
	{
		for(i=0;i<n;i++)
		{
			if(mass[x[st]][i]==1)
			{
				if((y[i]==-1)||y[i]>y[x[st]]+1)
			{
				x[en]=i;
				y[i]=y[x[st]]+1;
				en++;
				if(en==1000)en=0;
			}
			}
		}
		st++;
		if(st==1000)st=0;
	}
	if(y[n2-1]==-1)cout<<"Impossible";
	else cout<<y[n2-1];
	cin>>i;
	return 0;
}