import sys
import math

def f(x, Q, R, remain, p):
    if p == 1.0:
        b = Q * remain
    else:
        b = Q * ((1.0 - pow(p, x)) / (1.0 - p))
    a = (remain - x) * (Q - (1.0 - p) * R)
    return a + b

def main():
    N = int(sys.stdin.readline())
    X, Y = map(int, sys.stdin.readline().split())
    P, Q, R = map(float, sys.stdin.readline().split())

    ans = -1.0

    for t in range(N + 1):
        skill = X + t * Y
        remain = N - t

        if skill == 1:
            if remain == 1:
                ans = max(ans, P * t + Q)
            else:
                ans = max(ans, P * t + (Q - R) * (remain - 1) + Q)
            continue

        p = 1.0 - 1.0 / skill

        left = 0
        right = remain
        while right - left >= 3:
            cl = (left * 2 + right) // 3
            cr = (left + right * 2) // 3
            fcl = f(cl, Q, R, remain, p)
            fcr = f(cr, Q, R, remain, p)
            if fcl < fcr:
                left = cl
            else:
                right = cr

        for i in range(left, right + 1):
            ans = max(ans, P * t + f(i, Q, R, remain, p))

    print(f"{ans:.10f}")

if __name__ == "__main__":
    main()