#include<stdio.h>
#include <vector>
#include <list>
#include <map>
#include <set>
#include <queue>
#include <stack>
#include <algorithm>
#include <sstream>
#include <iostream>
#include <string>

using namespace std;

int main() {

	string s, ans;
	cin >> s;

	for (int i = 0; i < s.size(); i++) {
		char tmp;

		tmp = (26000 + (s[i] - 'A') - (i + 1)) % 26 + 'A';

		ans += tmp;
	}

	cout << ans << endl;

	return 0;
}