import math



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



h=x/(a*a)

if h>(b/2):

    c=(b-h)*2

    ans = math.atan2(c,a)

else:

    d=2*a*h/b

    ans=math.atan2(b,d)

print((math.degrees(ans)))
import sys

input = sys.stdin.readline



def I(): return int(eval(input()))

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

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



def main():

    import math

    mod=10**9+7

    a,b,x3=MI()

    

    x=x3/(a**2) #引数勘違いしてた

    

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

        y=(2*a*x)/b

        th=math.atan2(b,y)

        

    else:

        rem=a*(b-x)

        z=rem*2/a

        th=math.atan2(z,a)

        

    print((th/math.pi * 180))

        



main()

import math

a, b, x = list(map(int, input().split()))
h = x / (a * a)
if h > (b / 2):
    c = (b - h) * 2
    ans = math.atan2(c, a)
else:
    d = 2 * a * h / b
    ans = math.atan2(b, d)
print((math.degrees(ans)))

import sys

input = sys.stdin.readline


def I():
    return int(eval(input()))


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


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


def main():
    import math

    mod = 10**9 + 7
    a, b, x3 = MI()
    x = x3 / (a**2)  # 引数勘違いしてた
    if (a * b) // 2 >= a * x:
        y = (2 * a * x) / b
        th = math.atan2(b, y)
    else:
        rem = a * (b - x)
        z = rem * 2 / a
        th = math.atan2(z, a)
    print((th / math.pi * 180))


main()

-import math +import sys -a, b, x = list(map(int, input().split())) -h = x / (a * a) -if h > (b / 2): -    c = (b - h) * 2 -    ans = math.atan2(c, a) -else: -    d = 2 * a * h / b -    ans = math.atan2(b, d) -print((math.degrees(ans))) +input = sys.stdin.readline + + +def I(): +    return int(eval(input())) + + +def MI(): +    return list(map(int, input().split())) + + +def LI(): +    return list(map(int, input().split())) + + +def main(): +    import math + +    mod = 10**9 + 7 +    a, b, x3 = MI() +    x = x3 / (a**2)  # 引数勘違いしてた +    if (a * b) // 2 >= a * x: +        y = (2 * a * x) / b +        th = math.atan2(b, y) +    else: +        rem = a * (b - x) +        z = rem * 2 / a +        th = math.atan2(z, a) +    print((th / math.pi * 180)) + + +main()