#include <iostream>
#include <list>
using namespace std;

int main() {
    list<int> l1;
    l1.push_front(1);
    l1.push_front(2);
    l1.push_front(3);
    l1.push_back(4);
    l1.push_back(5);


    l1.pop_front();
    l1.pop_back();

    list<int>::iterator it = l1.begin();
    advance(it, 1);
    l1.erase(it);

    for(list<int>::iterator it = l1.begin(); it != l1.end(); it++) {
        cout << *it << " ";
    }

    return 0;
}