using System;

public class Program
{
	public static void Main()
	{
		string line = Console.ReadLine();
		for (int i = 0; i < line.Length; i++)
		{
			Console.Write((char)((line[i] - 'A' - (i + 1) + 26) % 26 + 'A'));
		}
		Console.WriteLine();
	}
}