#include <iostream>
#include <set>

using namespace std ;

int main()
{
	set<char> set1 ;
	set1.insert('G');
	set1.insert('F');
	set1.insert('G');
	for (char ch1 : set1)
	{
		cout << ch1 << ' ';
	}
	cout << '\n';

    if ( set1.count( 'G' ) > 0 )
      cout << "G found in set. " << endl ;

    //another way
    if (set1.find('G') != set1.end() )
      cout << "G found in set. " << endl ;

    set1.erase( 'G' ) ;
    if (set1.find('G') == set1.end() )
      cout << "G not found in set. " << endl ;


	return 0;
}