import math

a,b,x = list(map(int,input().split()))

x /= a

if x >= a*b/2:

    print((math.atan(2/(a**2)*(a*b-x))/math.pi*180)) 

else:

    print((90-(math.atan((2*x/b**2))/math.pi*180)))
import math

p = 3.14159

a,b,x = list(map(int,input().split()))

x /= a

if x >= a*b/2:

    print((math.atan(2/(a**2)*(a*b-x))/p*180)) 

else:

    print((90-(math.atan((2*x/b**2))/p*180)))
import math

a, b, x = list(map(int, input().split()))
x /= a
if x >= a * b / 2:
    print((math.atan(2 / (a**2) * (a * b - x)) / math.pi * 180))
else:
    print((90 - (math.atan((2 * x / b**2)) / math.pi * 180)))

import math

p = 3.14159
a, b, x = list(map(int, input().split()))
x /= a
if x >= a * b / 2:
    print((math.atan(2 / (a**2) * (a * b - x)) / p * 180))
else:
    print((90 - (math.atan((2 * x / b**2)) / p * 180)))

+p = 3.14159 -    print((math.atan(2 / (a**2) * (a * b - x)) / math.pi * 180)) +    print((math.atan(2 / (a**2) * (a * b - x)) / p * 180)) -    print((90 - (math.atan((2 * x / b**2)) / math.pi * 180))) +    print((90 - (math.atan((2 * x / b**2)) / p * 180)))