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