x,y,h=map(int, input().split())
x*=1000
y*=1000
if x>y:
    cnt=0 
    while y>h:
        cnt+=1 
        y/=2
        h*=2
    while x>h:
        cnt+=1 
        x/=2 
        h*=2
else:
    cnt=0 
    while x>h:
        cnt+=1 
        x/=2 
        h*=2
    while y>h:
        cnt+=1 
        y/=2
        h*=2
print(cnt)