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():
    ent = input().split()
    a = int(ent[0])
    b = int(ent[1])
    c = int(ent[2])
    d = int(ent[3])
    # sum{i=0 ate inf} de x*((1-x)*(1-y))**i
    a0 = a/b
    r = (1-(a/b)) * (1-(c/d))
    res = a0/(1-r)
    print(res)
    return

main()
	  	 		   		 	 	  		 	 				   	