#include <bits/stdc++.h> 

using namespace std;

int main() {
    string S, oS;
    cin >> S;
    for (int i = 0; i < S.length(); i++) {
        int num = (int)(S[i] - 'A') - (i + 1);
        while (num < 0)
            num += 26;
        oS += (char)('A' + num);
    }
    cout << oS << endl;
}