#include <bits/stdc++.h>

using namespace std;


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

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