import numpy as np

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

if x >= a*a*b/2:

    l = 2*b - 2*x/(a**2)

    print((np.rad2deg(np.arctan(l/a))))

else:

    l = 2*x/(a*b)

    print((np.rad2deg(np.arctan(b/l))))
import math

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

if x >= a*a*b/2:

    l = 2*b - 2*x/(a**2)

    print((math.degrees(math.atan(l/a))))

else:

    l = 2*x/(a*b)

    print((math.degrees(math.atan(b/l))))
import numpy as np

a, b, x = list(map(int, input().split()))
if x >= a * a * b / 2:
    l = 2 * b - 2 * x / (a**2)
    print((np.rad2deg(np.arctan(l / a))))
else:
    l = 2 * x / (a * b)
    print((np.rad2deg(np.arctan(b / l))))

import math

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

-import numpy as np +import math -    print((np.rad2deg(np.arctan(l / a)))) +    print((math.degrees(math.atan(l / a)))) -    print((np.rad2deg(np.arctan(b / l)))) +    print((math.degrees(math.atan(b / l))))