#include <bits/stdc++.h>
using namespace std;
int main() {
  int n;
  scanf("%d\n", &n);
  if (n & 1) {
    n--;
    putchar(getchar());
  }
  for (int i = 0; i < n - 2; i += 2) {
    putchar(getchar());
    putchar(getchar());
    putchar('-');
  }
  putchar(getchar());
  putchar(getchar());
  return 0;
}
