from scipy.sparse.csgraph import shortest_path, floyd_warshall, dijkstra, bellman_ford, johnson, minimum_spanning_tree

from scipy.sparse import csr_matrix, coo_matrix, lil_matrix

import numpy as np

from collections import deque, Counter, defaultdict

from itertools import product, permutations,combinations

from operator import itemgetter

from heapq import heappop, heappush

from bisect import bisect_left, bisect_right, bisect

from fractions import gcd

from math import ceil,floor, sqrt, cos, sin, pi, factorial

import math

from functools import reduce

import sys

read = sys.stdin.buffer.read

readline = sys.stdin.buffer.readline

readlines = sys.stdin.buffer.readlines

sys.setrecursionlimit(10**8)

INF = float('inf')

MOD = 10**9+7

def lcm_base(a, b):

    return (a * b) // gcd(a, b)



def lcm_list(numbers):

    return reduce(lcm_base, numbers, 1)





def main():

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

  V = a*a*b/2

  if V < x:

    ans = math.degrees(math.atan((2*(a*a*b-x))/a**3))

  else:

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

  print(ans)

  

  

  

if __name__ == '__main__':

  main()
import sys

import math



read = sys.stdin.read

readline = sys.stdin.buffer.readline

sys.setrecursionlimit(10 ** 8)

INF = float('inf')

MOD = 10 ** 9 + 7





def main():

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

    V = a * a * b / 2

    if V < x:

        ans = math.degrees(math.atan((2 * (a * a * b - x)) / a ** 3))

    else:

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

    print(ans)





if __name__ == '__main__':

    main()

from scipy.sparse.csgraph import (
    shortest_path,
    floyd_warshall,
    dijkstra,
    bellman_ford,
    johnson,
    minimum_spanning_tree,
)
from scipy.sparse import csr_matrix, coo_matrix, lil_matrix
import numpy as np
from collections import deque, Counter, defaultdict
from itertools import product, permutations, combinations
from operator import itemgetter
from heapq import heappop, heappush
from bisect import bisect_left, bisect_right, bisect
from fractions import gcd
from math import ceil, floor, sqrt, cos, sin, pi, factorial
import math
from functools import reduce
import sys

read = sys.stdin.buffer.read
readline = sys.stdin.buffer.readline
readlines = sys.stdin.buffer.readlines
sys.setrecursionlimit(10**8)
INF = float("inf")
MOD = 10**9 + 7


def lcm_base(a, b):
    return (a * b) // gcd(a, b)


def lcm_list(numbers):
    return reduce(lcm_base, numbers, 1)


def main():
    a, b, x = list(map(int, readline().split()))
    V = a * a * b / 2
    if V < x:
        ans = math.degrees(math.atan((2 * (a * a * b - x)) / a**3))
    else:
        ans = math.degrees(math.atan((a * b * b) / (2 * x)))
    print(ans)


if __name__ == "__main__":
    main()

import sys
import math

read = sys.stdin.read
readline = sys.stdin.buffer.readline
sys.setrecursionlimit(10**8)
INF = float("inf")
MOD = 10**9 + 7


def main():
    a, b, x = list(map(int, readline().split()))
    V = a * a * b / 2
    if V < x:
        ans = math.degrees(math.atan((2 * (a * a * b - x)) / a**3))
    else:
        ans = math.degrees(math.atan((a * b * b) / (2 * x)))
    print(ans)


if __name__ == "__main__":
    main()

-from scipy.sparse.csgraph import ( -    shortest_path, -    floyd_warshall, -    dijkstra, -    bellman_ford, -    johnson, -    minimum_spanning_tree, -) -from scipy.sparse import csr_matrix, coo_matrix, lil_matrix -import numpy as np -from collections import deque, Counter, defaultdict -from itertools import product, permutations, combinations -from operator import itemgetter -from heapq import heappop, heappush -from bisect import bisect_left, bisect_right, bisect -from fractions import gcd -from math import ceil, floor, sqrt, cos, sin, pi, factorial +import sys -from functools import reduce -import sys -read = sys.stdin.buffer.read +read = sys.stdin.read -readlines = sys.stdin.buffer.readlines - - -def lcm_base(a, b): -    return (a * b) // gcd(a, b) - - -def lcm_list(numbers): -    return reduce(lcm_base, numbers, 1)