from fractions import Fraction
a1, a2, a3 = map(int, input().split())
if a2 != 0:
    x = Fraction(a2**2-a1*a3) / Fraction(a3-a2)
    r = Fraction(a2) / Fraction(a1+x)
    d = Fraction(a2 - a1*r)
else:
    d = a3
    r = -d / a1
print(round(r*a3+d))