#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, i, j, two, three;
  char c[110];
  cin >> n;
  while (cin.fail() == false) {
    cin >> c;
    for (i = 0; i < 51; i++) {
      for (j = 0; j < 35; j++) {
        if (i * 2 + j * 3 == n) {
          two = i;
          three = j;
          i = 100;
          j = 100;
          break;
        }
      }
    }
    int k = 0;
    for (i = 0; i < two; i++) {
      cout << c[k] << c[k + 1];
      k += 2;
      if (k < n - 1) {
        cout << "-";
      }
    }
    for (i = 0; i < three; i++) {
      cout << c[k] << c[k + 1] << c[k + 2];
      k += 3;
      if (k < n - 1) {
        cout << "-";
      }
    }
    cout << endl;
    cin >> n;
  }
  return 0;
}
