#include <bits/stdc++.h>

using namespace std;
void fast_io() {
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
}

int main() {
    fast_io();
    char c;
    cin >> c;
    if (string("ACDFG").find(c) != string::npos) {
        cout << c << "#\n";
    } else {
        c++;
        cout << c << "\n";
    }
}