#include <bits/stdc++.h>
using namespace std;
using ll = long long;
#define rep(i, s, e) for (int i = (int)s; i < (int)e; i++)

int main() {
    cin.tie(nullptr);
    
    string S;
    cin >> S;
    
    int len = S.size();
    
    rep(i, 0, len) {
        S[i] = (S[i] - 'A' - i - 1 + 260000) % 26 + 'A';
    }
    
    cout << S << '\n';
}