SmallR is an archer. SmallR is taking a match of archer with Zanoes. They try to shoot in the target in turns, and SmallR shoots first. The probability of shooting the target each time is <img align="middle" class="tex-formula" src="https://espresso.codeforces.com/a7487d7e62f90136b78ae3fbf0a008396f146e13.png" style="max-width: 100.0%;max-height: 100.0%;"/> for SmallR while <img align="middle" class="tex-formula" src="https://espresso.codeforces.com/c443c7703e51f03d0eece0b96b9e84e425878209.png" style="max-width: 100.0%;max-height: 100.0%;"/> for Zanoes. The one who shoots in the target first should be the winner.

Output the probability that SmallR will win the match.
A single line contains four integers <img align="middle" class="tex-formula" src="https://espresso.codeforces.com/488158367221f441ba94b9475c03436069df2a7e.png" style="max-width: 100.0%;max-height: 100.0%;"/>.
def main():
    a, b, c, d = map(int, input().split())
    acerto_1 = a/b
    acerto_2 = c/d
    erro_1 = 1-acerto_1 
    erro_2 = 1-acerto_2
    soma_probs = acerto_1
    probabilidade_vitoria = acerto_1
    while (soma_probs > 10**-6):
        soma_probs = soma_probs*erro_1*erro_2
        probabilidade_vitoria += soma_probs
    print(probabilidade_vitoria)
main()