#!/usr/bin/env python3
import sys
input = sys.stdin.readline

x, y, h = map(int, input().split())
h *= 0.001
if x > y:
    x, y = y, x

cnt = 0
while x > h:
    h *= 2
    x /= 2.0
    cnt += 1
while y > h:
    h *= 2
    y /= 2.0
    cnt += 1
print(cnt)