题解 | #游游开车出游#

from math import sqrt

v, x, y = map(int, input().split())
"""
x*f(t) = t + y/(v+tx) = (v + tx) + xy/(v+tx) - v >= 2*sqrt(xy) - v
当且仅当 t + v/x = xy/(v+tx) 时取到最小
t = (sqrt(y*x) - v)/ x
"""
t = (sqrt(y*x) - v) / x
if t < 0:
    t = 0
res = y/(v + t*x) + t
print(res)