#include <bits/stdc++.h>
using namespace std;
int main() {
  ios_base::sync_with_stdio(0);
  int n, i;
  string s;
  cin >> n;
  cin >> s;
  if (n == 2)
    cout << s;
  else if (n == 3)
    cout << s;
  else {
    if (s.length() % 2 == 0) {
      int x = s.length() / 2 - 1, cnt = 0;
      for (i = 2; i < s.length(); i += 3) {
        ++cnt;
        s.insert(i, "-");
        if (cnt == x) break;
      }
      cout << s << endl;
      return 0;
    } else {
      int x = s.length() / 2 - 1, cnt = 0;
      for (i = 2; i < s.length(); i += 3) {
        ++cnt;
        s.insert(i, "-");
        if (cnt == x) break;
      }
      cout << s << endl;
      return 0;
    }
  }
  return 0;
}
