import sys

from math import atan,pi

def main():

    input = sys.stdin.readline

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

    x /= a

    t = 0

    if 2*x < a * b:

        t = atan(b*b/2/x)

    elif 2*x > a * b:

        t = atan((2*a*b-2*x)/a/a)

    else:

        t = pi/4

    ans = t * 180 / pi

    print(ans)





if __name__ == '__main__':

    main()
from math import atan, pi



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

if a * a * b > 2 * x:

    ans = atan(a * b * b / 2 / x)

else:

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



ans *= 180 / pi

print(ans)

import sys
from math import atan, pi


def main():
    input = sys.stdin.readline
    a, b, x = list(map(int, input().split()))
    x /= a
    t = 0
    if 2 * x < a * b:
        t = atan(b * b / 2 / x)
    elif 2 * x > a * b:
        t = atan((2 * a * b - 2 * x) / a / a)
    else:
        t = pi / 4
    ans = t * 180 / pi
    print(ans)


if __name__ == "__main__":
    main()

from math import atan, pi

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

-import sys - -def main(): -    input = sys.stdin.readline -    a, b, x = list(map(int, input().split())) -    x /= a -    t = 0 -    if 2 * x < a * b: -        t = atan(b * b / 2 / x) -    elif 2 * x > a * b: -        t = atan((2 * a * b - 2 * x) / a / a) -    else: -        t = pi / 4 -    ans = t * 180 / pi -    print(ans) - - -if __name__ == "__main__": -    main() +a, b, x = list(map(int, input().split())) +if a * a * b > 2 * x: +    ans = atan(a * b * b / 2 / x) +else: +    ans = atan((2 * a * a * b - 2 * x) / a / a / a) +ans *= 180 / pi +print(ans)