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