What will be the output of the following C++ code?

#include <iostream> 
#include <vector> 
#include <forward_list>  
 
using namespace std; 
 
int main() 
{ 
    forward_list<int> fl1;
    fl1.assign(5,10);
    for (int&c : fl1)  
        cout << c << " ";
    cout<<endl;
    fl1.insert_after(fl1.begin(), {1,2,3});
    for (int&c : fl1)  
        cout << c << " ";
    cout<<endl; 
    return 0; 
}