from math import atan, pi

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



if x > (a ** 2 * b / 2):

    print((atan(2 * (a ** 2 * b - x) / a ** 3) * 180 / pi))

else:

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



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



if a ** 2 * b == x:

    print((0.0))

elif a ** 2 * b * 0.5 < x:

    d = a ** 3 / (2 * (a ** 2 * b - x))

    print((90 - math.atan(d) * 180 / math.pi))

else:

    d = 2 * x / (a * b ** 2)

    print((90 - math.atan(d) * 180 / math.pi))

from math import atan, pi

a, b, x = list(map(int, input().split()))
if x > (a**2 * b / 2):
    print((atan(2 * (a**2 * b - x) / a**3) * 180 / pi))
else:
    print((atan((a * b**2) / (2 * x)) * 180 / pi))

import math

a, b, x = list(map(int, input().split()))
if a**2 * b == x:
    print((0.0))
elif a**2 * b * 0.5 < x:
    d = a**3 / (2 * (a**2 * b - x))
    print((90 - math.atan(d) * 180 / math.pi))
else:
    d = 2 * x / (a * b**2)
    print((90 - math.atan(d) * 180 / math.pi))

-from math import atan, pi +import math -if x > (a**2 * b / 2): -    print((atan(2 * (a**2 * b - x) / a**3) * 180 / pi)) +if a**2 * b == x: +    print((0.0)) +elif a**2 * b * 0.5 < x: +    d = a**3 / (2 * (a**2 * b - x)) +    print((90 - math.atan(d) * 180 / math.pi)) -    print((atan((a * b**2) / (2 * x)) * 180 / pi)) +    d = 2 * x / (a * b**2) +    print((90 - math.atan(d) * 180 / math.pi))