#include <iostream>
#include <string>
using namespace std;

int main()
{
	string s;
	cin >> s;
	
	for( int i = 0; i < s.length(); i++ ){
		for( int j = 0; j < i + 1; j++ ){
			if( s[i] == 'A' )
				s[i] = 'Z';
			else
				s[i]--;
		}
	}
	cout << s << endl;
	return 0;
}