//TLE解法

#include <bits/stdc++.h>
using namespace std;
using ll = long long;
#define all(A) A.begin(),A.end()
using vll = vector<ll>;
#define rep(i, n) for (long long i = 0; i < (long long)(n); i++)

ll gcd(ll(a), ll(b)) {
	ll c = a;
	while (a % b != 0) {
		c = a % b;
		a = b;
		b = c;
	}
	return b;
}
vll DP(300005,1e18);
ll dfs(ll n){
	if(n==1){
		DP[1]=0;
		return 0;
	}
	ll res=1e18;
	if(DP[n]<1e17)return DP[n];
	for(ll i=1;i*i<=n;i++){
		//cout<<n<<endl;
		if(n%i==0){
			if(DP[i]>1e17)dfs(i);
			res=min(res,DP[i]+n/i);
			if(i!=1)if(DP[n/i]>1e17)dfs(n/i);
			res=min(res,DP[n/i]+i);
			
		}
	}
	DP[n]=res;
	return res;
}


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