func main()
	var ss: [][]char :: cui@input().split(" ")
	var a: int :: ss[0].toInt(&)
	var b: int :: ss[1].toInt(&)
	var ans: int :: 0
	for i(23, 25)
		if(a <= i & i <= b)
			skip i
		end if
		do ans :+ 1
	end for
	do cui@print("\{ans}\n")
end func