using System; using System.Collections.Generic; using System.Linq; class Program { public static void Main() { char[] S = Console.ReadLine().ToArray(); char[] R = new Char[S.Length]; for (int i = 0;i < S.Length; ++i) { R[i] = ToAscii(S[i],i + 1); } Console.WriteLine($"{string.Join("",R)}"); } private static char ToAscii(char c,int n) { int code = (int)c + 26 - (n % 26); if (code > 90) { code -= 26; } return (char)(code); } }