#define _GLIBCXX_DEBUG
#define ll long long
#include <bits/stdc++.h>
using namespace std;
using Graph = vector<vector<int>>;

int main(){
  string S; cin >> S;
  if(S != "E" and S != "B") cout << S << '#' << endl;
  else if(S == "E") cout << "F" << endl;
  else cout << "C" << endl;
}