#include <iostream>

using std::cin;
using std::cout;
#include "func.h"

int main() {
  int n, m; cin >> n;
  MyString a, b, c;
  read(a, n); read(b, n);
  c = merge(a, b);
  print(a);
  print(b);
  print(c);
  del(a);
  del(b);
  del(c);
}