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

int main() {
	string s;
	cin >> s;
	
	for(int i=0;i<s.size();i++){
		int a = i+1;
		while(s[i] - a < 'A'){
			a -= 26;
		}
		s[i] = s[i] -a;
	}
	cout << s << endl;
	
	return 0;
}