import math
a, b, x = map(int, input().split())
s = x / a
if s >= a * b / 2:
    h = (a * b - s) * 2 / a
    r = math.atan2(h, a)
else:
    w = 2 * s / b
    r = math.atan2(b, w)
d = r * 180 / math.pi
print(d)

39d0c7b61a85499e9101aa2403da5a7f6bf3e534
<mask token>

<mask token>
if s >= a * b / 2:
    h = (a * b - s) * 2 / a
    r = math.atan2(h, a)
else:
    w = 2 * s / b
    r = math.atan2(b, w)
<mask token>
print(d)

<mask token>
a, b, x = map(int, input().split())
s = x / a
if s >= a * b / 2:
    h = (a * b - s) * 2 / a
    r = math.atan2(h, a)
else:
    w = 2 * s / b
    r = math.atan2(b, w)
d = r * 180 / math.pi
print(d)

import math
a, b, x = map(int, input().split())
s = x / a
if s >= a * b / 2:
    h = (a * b - s) * 2 / a
    r = math.atan2(h, a)
else:
    w = 2 * s / b
    r = math.atan2(b, w)
d = r * 180 / math.pi
print(d)
