x,y,h=map(int,input().split())
ANS=0
x*=1000
y*=1000

from fractions import Fraction

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