func main()
	var ss: [][]char :: cui@input().split(" ")
	var x: int :: ss[0].toInt(&) * 1000
	var y: int :: ss[1].toInt(&) * 1000
	var h: int :: ss[2].toInt(&)
	var ans: int :: 0
	while(x > h)
		do h :* 4
		do y :* 2
		do ans :+ 1
	end while
	while(y > h)
		do h :* 4
		do ans :+ 1
	end while
	do cui@print("\{ans}\n")
end func