#include <bits/stdc++.h>
using namespace std;
#include <atcoder/all>
using namespace atcoder;

typedef unsigned int uint;
typedef long long int ll;
typedef unsigned long long ull;
typedef long double ld;

#define loop while(1)
#define rep(i,n) for(ll i=0;(i)<(n);(i)++)
#define REP(i,a,n) for(ll i=(a);(i)<(n);(i)++)
#define modi(a,b) (a%b+b)%b
#define all(x) x.begin(), x.end()
#define debug(x) cerr << #x << " = " << x << endl
#define dout()  cout << fixed << setprecision(20)

int main(){
  char ABC;
  cin >> ABC;
  if(ABC == 'B') cout << 'C' << endl;
  else if(ABC == 'E') cout << 'F' << endl;
  else cout << ABC << '#' << endl;
}