#include <bits/stdc++.h>
using namespace std;

#define SZ(a) (int)a.size()
#define ALL(a) a.begin(), a.end()
#define FOR(i, a, b) for (int i = (a); i<(b); ++i)
#define RFOR(i, b, a) for (int i = (b)-1; i>=(a); --i)
#define MP make_pair
#define PB push_back
#define F first
#define S second
#define FILL(a, b) memset(a, b, sizeof(a))

typedef long long LL;
typedef pair<int, int> PII;
typedef vector<int> VI;

int main()
{
	ios::sync_with_stdio(false);
	cin.tie(0);
	int p, a, b, c, d, n;
	cin >> p >> a >> b >> c >> d >> n;
	
	long double ans = 0, mx = 0.0;
	FOR(k, 1, n + 1){
		long double cur = sin(a * k + b) + cos(c * k + d) + 2;
		ans = max(ans, mx - cur);
		mx = max(mx, cur);
	}
	cout << fixed << setprecision(10) << ans * p << endl;
	
	
	return 0;
}