#include <bits/stdc++.h>
using namespace std;
int main() {
  int n;
  cin >> n;
  int a = 0;
  int ok = 0;
  if (n == 3 || n == 2) {
    string s;
    cin >> s;
    cout << s;
    return 0;
  }
  for (int i = 1; i <= n; i++) {
    a++;
    char x;
    cin >> x;
    cout << x;
    if (n % 2 != 0 && ok == 0) {
      if (a == 3) {
        a = 0;
        cout << "-";
        ok = 1;
      }
    }
    if (a == 2 && i != n && (ok || n % 2 == 0)) {
      cout << "-";
      a = 0;
    }
  }
  return 0;
}
