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