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():
    abcd = input().split()
    hitS = int(abcd[0]) / int(abcd[1])
    missS = 1 - hitS
    hitZ = int(abcd[2]) / int(abcd[3])
    missZ = 1 - hitZ
    soma = 0
    for i in range(15):
        soma += (missS**i) * (missZ**i)
    print(hitS * soma)

main()
 	 			 	  		 	  		 			 	 	 		