import sys; input = sys.stdin.buffer.readline
sys.setrecursionlimit(10**7)
from collections import defaultdict
con = 10 ** 9 + 7; INF = float("inf")

def getlist():
	return list(map(int, input().split()))

#処理内容
def main():
	x, y, h = getlist()
	x *= 1000; y *= 1000
	x, y = list(sorted([x, y]))
	ans = 0
	while x > h:
		y *= 2; h *= 4
		ans += 1

	while y > h:
		h *= 4
		ans += 1

	print(ans)

if __name__ == '__main__':
	main()