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 find_prob(a, b, c, d):
    k1 = a / b
    k2 = (1 - (a / b))
    k3 = (1 - (c / d))
    ans = k1
    i = 1
    x = 1
    y = k1
    while i < 1000000:
        x = ans
        y += k1 * (k2 ** i) * (k3 ** i)
        ans = y
        i += 1
    return ans

l = list(map(int, input().split()))
print(find_prob(l[0], l[1], l[2], l[3]))
	   			 	  				  	 	   	 		