#include <bits/stdc++.h>
using namespace std;
int main() {
  int n;
  cin >> n;
  string s;
  cin >> s;
  if (n <= 3)
    cout << s << endl;
  else if (n % 2 == 0) {
    int i = 2;
    while (s[i] != '\0') {
      s.insert(i, "-");
      i += 3;
    }
    cout << s << endl;
  } else if (n % 2 != 0) {
    s.insert(3, "-");
    int i = 6;
    while (s[i] != '\0') {
      s.insert(i, "-");
      i += 3;
    }
    cout << s << endl;
  }
}
