func main()
	var S: []char :: cui@input()
	for n(1, ^S)
		var oldId: int :: S[n - 1] $ int - 'A' $ int
		var newId: int :: (oldId + 25 * n) % 26
		do S[n - 1] :: 'A'.offset(newId)
	end for
	
	var ans: []char :: S
	do cui@print("\{ans}\n")
end func