#include <bits/stdc++.h>
using namespace std;
double f(int x, double Q, double R, int remain, double p){
	double a = (remain - x) * (Q - (1.0 - p) * R);// もみ消す
	double b = Q * ((1.0 - pow(p, x)) / (1.0 - p)); // クビになる(ゼロ除算に注意)
	return a + b;
}
int main(void){
	int N, X, Y;
	cin >> N >> X >> Y;
	double P, Q, R;
	cin >> P >> Q >> R;
	double ans = -1.0;
	for (int t = 0; t <= N; t++) {
		int skill = X + t * Y;
		double p = 1.0 - 1.0 / skill;
		int remain = N - t;
		if (skill == 1) { // 必ず卵をかけてしまう場合
			if (remain == 1) {
				ans = max(ans, P * t + Q);
			} else {
				ans = max(ans, P * t + (Q - R) * (remain - 1) + Q);
			}
			continue;
		}
		int left = 0, right = remain;
		while (3 <= right - left) {
			int cl = (left * 2 + right) / 3;
			int cr = (left + right * 2) / 3;
			double fcl = f(cl, Q, R, remain, p);
			double fcr = f(cr, Q, R, remain, p);
			if (fcl < fcr) {
				left = cl;
			} else {
				right = cr;
			}
		}
		for (int i = left; i <= right; i++) {
			ans = max(ans, P * t + f(i, Q, R, remain, p));
		}
	}
	cout << fixed << setprecision(10) << ans << endl;
}