func main()
	var s: []char :: cui@input()
	var ans: int :: 0
	var cnt: int :: 0
	for i(^s - 1, 0, -1)
		switch(s[i])
		case 'c'
			do ans :+ cnt * (cnt - 1) / 2
		case 'w'
			do cnt :+ 1
		end switch
	end for
	do cui@print("\{ans}\n")
end func