#include <bits/stdc++.h>
using namespace std;
int main() {
  int n;
  cin >> n;
  string str1, str2 = "-";
  cin >> str1;
  if (n == 2 || n == 3) {
    cout << str1 << endl;
    return 0;
  }
  if (n % 2 == 0) {
    for (int i = 2; i < str1.size(); i += 3) {
      str1.insert(i, str2);
    }
    cout << str1 << endl;
  } else if (n % 2 != 0) {
    for (int i = 2; i < str1.size() - 1; i += 3) {
      str1.insert(i, str2);
    }
    cout << str1 << endl;
  }
}
