import java.util.Scanner;

public class DRMMessagesDavid
{
	public static void main(String[] args) 
	{
		Scanner scan = new Scanner(System.in);
		String encrypted = scan.next();
		scan.close();
		
		System.out.println(Decrypt(encrypted));
	}

	private static String Decrypt(String encrypted) 
	{
		String p1 = encrypted.substring(0, encrypted.length() / 2);
		String p2 = encrypted.substring(encrypted.length() / 2);
		
		return Merge(Rotate(p1), Rotate(p2));
	}

	private static String Merge(String s1, String s2) 
	{
		char[] result = new char[s1.length()];
		for (int i = 0; i < s1.length(); i++)
		{
			result[i] = (char)((s1.charAt(i) - 'A' + s2.charAt(i) - 'A') % 26 + 'A');
		}
		
		return new String(result);
	}

	private static String Rotate(String s) 
	{
		char[] c = new char[s.length()];
		int rotation = GetRotationOfString(s);
		for (int i = 0; i < s.length(); i++)
		{
			c[i] = Rotate(s.charAt(i), rotation);
		}
		
		return new String(c);
	}

	private static char Rotate(char c, int rotation)
	{
		return (char)('A' + ((c - 'A' + rotation) % 26));
	}

	private static int GetRotationOfString(String s) 
	{
		int rotation = 0;
		for (int i = 0; i < s.length(); i++)
		{
			rotation += s.charAt(i) - 'A';
		}
		
		return rotation;
	}
}