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