#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, i;
  string s;
  cin >> n;
  cin >> s;
  while (n > 3) {
    cout << s[0] << s[1] << '-';
    s = s.substr(2);
    n -= 2;
  }
  cout << s;
}
