#include <bits/stdc++.h>
using namespace std;
int main() {
  int n;
  cin >> n;
  string s;
  cin >> s;
  string s1 = "";
  if (n % 2 == 0) {
    for (int i = 0; i < n; i++) {
      cout << s[i] << s[i + 1];
      i++;
      if (i < n - 2) {
        cout << "-";
      }
    }
  } else {
    if (n == 3)
      cout << s << endl;
    else {
      for (int i = 0; i < n; i++) {
        if (i == 0) {
          cout << s[i] << s[i + 1] << s[i + 2] << "-";
          i += 2;
          continue;
        } else {
          cout << s[i] << s[i + 1];
        }
        if (i < n - 2) {
          cout << "-";
        }
        i++;
      }
    }
  }
}
