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