#include <iostream>

using namespace std;

int main() {
    string s;
    cin >> s;
    for (int i = 0; i < s.length(); i++) {
        s[i] -= i+1;
        if (s[i] - 'A' < 0) s[i] += 26;
    }
    cout << s << '\n';
    return 0;
}