#include<cstdio>
#include<iostream>
#include<cmath>
using namespace std;
double h,s,v,l,k,n;
int answer=0;
int main()
{
	freopen ("freefaller.in","r",stdin);
	freopen ("freefaller.out","w",stdout);
	//scanf("%lf%lf%lf%lf%lf",&h,&s,&v,&l,&k,&n);
	cin>>h>>s>>v>>l>>k>>n;

	double t,y,y2;
	t=sqrt(0.2*(h-k));//t=√2*H/g  下落到车的顶部所需要的时间
	y=s-v*t;//在球下落到车顶时，车头距原点的距离
	y2=y+l; //车尾距原点的距离
	t=sqrt(0.2*(h));//下落到最底端所需时间
	y=s-v*t;//此时小车的位置

	for (int i=0;i<n;i++)
	{
		if (i>=y-0.00001 && i<=y2+0.00001)
		{
			answer++;
		}
	}

	printf("%d",answer);
	return 0;
}