#include <bits/stdc++.h>
using namespace std;
#define rep(i,n) for (int (i)=(0);(i)<(int)(n);++(i))
using ll = long long;
using P = pair<int, int>;
using namespace std;

int main() {
    string s;
    cin >> s;
    rep(i, s.size()) {
        s[i] = (((s[i]-'A') - (i+1) + 26*2000) % 26) + 'A';
    }
    cout << s << endl;
}