#include <bits/stdc++.h>

using namespace std;

void solve() {
    string S;
    cin >> S;
    if (S == "E") {
        cout << "F" << endl;
    } else if (S == "B") {
        cout << "C" << endl;
    } else {
        S += "#";
        cout << S << endl;
    }
}

int main() {
    ios::sync_with_stdio(false);
    cin.tie(0);
    solve();
    return 0;
}