#include <stdio.h>
#include<iostream>
#include<string>
using namespace std;
int main()
{
    string a;
    cin >> a;
    if (a=="GG")
    {
     cout << "FF";
    }
    else if(a == "SS")
    {
     int b;
     cin >> b;
     cout << a << b;
    }




    return 0;
}