func main()
	var s: []char :: cui@input()
	var t: []char :: #[^s]char
	var idx: int :: 0
	for i(0, ^s - 1)
		if(i = 0 | s[i] <> s[i - 1])
			do t[idx] :: s[i]
			do idx :+ 1
		end if
	end for
	do cui@print("\{t}\n")
end func