x,y,h=map(int,input().split())
ANS1=ANS2=0
x*=1000
y*=1000
x2=x
y2=y

from fractions import Fraction

while x>h:
    x=x*Fraction(1,2)
    h*=2
    ANS1+=1
while y>h:
    y=y*Fraction(1,2)
    h*=2
    ANS1+=1

x=y2
y=x2

while x>h:
    x=x*Fraction(1,2)
    h*=2
    ANS2+=1
while y>h:
    y=y*Fraction(1,2)
    h*=2
    ANS2+=1

print(max(ANS1,ANS2))