#include <set>
#include <iostream>
int main( )
{
using namespace std;
set <int> s1;
set <int> :: size_type i;
s1.insert( 1 );
i = s1.size( );
cout << "The set length is " << i << "." << endl;
s1.insert( 2 );
i = s1.size( );
cout << "The set length is now " << i << "." << endl;
}