#include <cmath>

#include <cstdio>

int n, ans;

double h, s1, v, l, k, r = 0.0001;

inline bool check(double x)

{

	double t1 = sqrt((h - k - r) / 5.0), t2 = sqrt(h / 5.0);

	double t3 = (s1 - x - r) / v, t4 = (s1 - x + l + r) / v;

	if(t1 > t4 || t2 < t3) return 0;

	return 1;

}

int main()

{

	scanf("%lf %lf %lf %lf %lf %d", &h, &s1, &v, &l, &k, &n);

	for(int i = 0; i < n; i++) ans += check(i);

	printf("%d\n", ans);

	return 0;

}