import math

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

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

    print((45))

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

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

else:

    print((math.degrees(math.atan(a*b**2/(2*x)))))

import math





def LI():

    return list(map(int, input().split()))





a, b, x = LI()

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

    ans = 45

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

    ans = math.degrees(math.atan((2*(b-x/(a**2)))/a))

else:

    ans = math.degrees(math.atan(a*b**2/(2*x)))

print(ans)

import math

a, b, x = list(map(int, input().split()))
if x == (a**2 * b) / 2:
    print((45))
elif x > (a**2 * b) / 2:
    print((math.degrees(math.atan((2 * (b - x / (a**2))) / a))))
else:
    print((math.degrees(math.atan(a * b**2 / (2 * x)))))

import math


def LI():
    return list(map(int, input().split()))


a, b, x = LI()
if x == (a**2 * b) / 2:
    ans = 45
elif x > (a**2 * b) / 2:
    ans = math.degrees(math.atan((2 * (b - x / (a**2))) / a))
else:
    ans = math.degrees(math.atan(a * b**2 / (2 * x)))
print(ans)

-a, b, x = list(map(int, input().split())) + +def LI(): +    return list(map(int, input().split())) + + +a, b, x = LI() -    print((45)) +    ans = 45 -    print((math.degrees(math.atan((2 * (b - x / (a**2))) / a)))) +    ans = math.degrees(math.atan((2 * (b - x / (a**2))) / a)) -    print((math.degrees(math.atan(a * b**2 / (2 * x))))) +    ans = math.degrees(math.atan(a * b**2 / (2 * x))) +print(ans)