#include <iostream>

using namespace std;

string S;

int main() {
    cin >> S;
    for (int i = 0; i < S.size(); i++) {
        char in = S.at(i);
        int n = (i + 1) % 26;
        char out = in - n;
        if (out < 'A') out += 26;
        cout << out;
    }
    cout << endl;
    return 0;
}