#include<bits/stdc++.h>
using namespace std;
int main()
{
	double H,s1,V,L,K,n,t=0;
	int sum=0;
	cin>>H>>s1>>V>>L>>K>>n;
	t=sqrt(H/5);
	for(int i=1;i<=n;i++)
	{
		double k1=s1+1-i,k2=s1+1+L-i;
		double t1=(k1-0.0001)/V,t2=(k2+0.0001)/V;
		if(t1<=t&&t2>=t)
		sum++;
	}
	cout<<sum;
	return 0;
}