# coding: utf-8
# Your code here!

import sys
sys.setrecursionlimit(10**6)
readline = sys.stdin.readline
read = sys.stdin.read

x,y,h = [int(i) for i in read().split()]

x*=1000
y*=1000

if x>y: x,y = y,x

ax = ay = 1
ans = 0
while h*ax<x or h*ay<y:
    if h*ax<x: ax *= 2
    else: ay *= 2
    h*=2
    ans += 1
    #print(h,x,y,ax,ay)

print(ans)