func main()
	var S: []char :: cui@input()
	var c: []int :: #[^S]int
	var lastC: int :: -1
	for i(0, ^S - 1)
		do c[i] :: lastC
		if(S[i] = 'c')
			do lastC :: i
		end if
	end for
	var lastW: int :: -1
	var notFound: int :: ^S + 1
	var ans: int :: notFound
	for i(^S - 1, 0, -1)
		if(S[i] = 'w')
			if(lastW <> -1 & c[i] <> -1)
				do ans :: [ans, (i - c[i]) + 1 + (lastW - i)].min()
			end if
			do lastW :: i
		end if
	end for
	if(ans = notFound)
		do ans :: -1
	end if
	do cui@print("\{ans}\n")
end func