#include <bits/stdc++.h>
using namespace std;
int main() {
  int n;
  cin >> n;
  string s;
  cin >> s;
  int cur = 0;
  for (int i = 2; i < n - 1; i += 2) {
    s.insert(s.begin() + i + cur, '-');
    cur++;
  }
  cout << s << endl;
  return 0;
}
