#include
#include
using namespace std;
int main()
{
list lst1, lst2;
int i;
for(i=0; i<10; i++) lst1.push_back(i);
for(i=0; i<10; i++) lst2.push_front(i);
list::iterator p;
p = lst1.begin();
while(p != lst1.end()) {
cout << *p << " ";
p++;
}
p = lst2.begin();
while(p != lst2.end()) {
cout << *p << " ";
p++;
}
return 0;
}