#include <list>
#include <set>
#include <iterator>
#include <iostream>

using namespace std;

int main() {
    list<int> destination = {1, 2, 3, 4, 5};
    set<int> source = {678, 901, 234, 567, 890, 123};

    auto it = destination.begin();
    advance(it, 3);					    // Why not it+=3?

    insert_iterator< list<int> > insert_it(destination,it); // Why > >?

    copy(source.begin(), source.end(), insert_it);

    for (auto v : destination)
	  cout << v << ' ';
    cout << '\n';
}