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

int main(){
    char c;
    cin >> c;
    string s = "ACDFG";
    rep(i,5){
        if(c==s[i]){
            cout << c << "#" << endl;
            return 0;
        }
    }
    cout << (char)(c+1) << endl;
    return 0;
}