#include <bits/stdc++.h>
using namespace std;

int main() {
	string s;
	cin >> s;

	for (int i = 0; i < s.size(); i++) {
		int n = (i + 1) % 26;
		int a = (int)s.at(i);
		a -= n;

		if (a < 65) {
			a = 91 - (65 - a);
		}
		//cout << a << endl;

		s.at(i) = (char)a;
	}

	cout << s << endl;
}