#!/usr/bin/env python3

import collections

import itertools as it

import math

#import numpy as np

 

#  = input()

#  = int(input())

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

#  = list(map(int, input().split()))

#  = [int(input()) for i in range(N)]

#

# c = collections.Counter()





def f(a, b, x):

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

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

    else:

        return math.pi / 2 - math.atan(2 * x / (a * b * b))



print((f(a, b, x) * 180 / math.pi))

#!/usr/bin/env python3

import collections

import itertools as it

import math

#import numpy as np

 

#  = input()

#  = int(input())

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

#  = list(map(int, input().split()))

#  = [int(input()) for i in range(N)]

#

# c = collections.Counter()





def f(a, b, x):

    """

    """

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

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

    else:

        return math.pi / 2 - math.atan(2 * x / (a * b * b))



#print(f(a, b, x) * 180 / math.pi)

print((math.degrees(f(a, b, x))))

#!/usr/bin/env python3
import collections
import itertools as it
import math

# import numpy as np
#  = input()
#  = int(input())
a, b, x = list(map(int, input().split()))
#  = list(map(int, input().split()))
#  = [int(input()) for i in range(N)]
#
# c = collections.Counter()
def f(a, b, x):
    if a * a * b / 2 <= x:
        return math.atan(2 * (a * a * b - x) / (a * a * a))
    else:
        return math.pi / 2 - math.atan(2 * x / (a * b * b))


print((f(a, b, x) * 180 / math.pi))

#!/usr/bin/env python3
import collections
import itertools as it
import math

# import numpy as np
#  = input()
#  = int(input())
a, b, x = list(map(int, input().split()))
#  = list(map(int, input().split()))
#  = [int(input()) for i in range(N)]
#
# c = collections.Counter()
def f(a, b, x):
    """ """
    if a * a * b / 2 <= x:
        return math.atan(2 * (a * a * b - x) / (a * a * a))
    else:
        return math.pi / 2 - math.atan(2 * x / (a * b * b))


# print(f(a, b, x) * 180 / math.pi)
print((math.degrees(f(a, b, x))))

+    """ """ -print((f(a, b, x) * 180 / math.pi)) +# print(f(a, b, x) * 180 / math.pi) +print((math.degrees(f(a, b, x))))