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

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