x,y,h=list(map(int,input().split()))
n=0
h=h/1000
x=max(x,y)
y=min(x,y)
while True:
    if y>h:
        y=y/2
        h=h*2
        n=n+1
    else:
        break
while True:
    if x>h:
        x=x/2
        h=h*2
        n=n+1
    else:
        break
print(n)