#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, x = 0, tmp = 0;
  string num;
  cin >> n >> num;
  int len = num.size();
  if (n == 2 || n == 3) {
    cout << num << endl;
  } else if (n % 2 == 0) {
    for (int i = 0; i < len; i++) {
      ++x;
      cout << num[i];
      if (x == 2 && tmp != (n / 2) - 1) {
        cout << '-';
        x = 0;
        ++tmp;
      }
    }
    cout << endl;
  } else {
    x = 0, tmp = 0;
    for (int i = 0; i < len - 3; i++) {
      ++x;
      cout << num[i];
      if (x == 2 && tmp != (len - 3) / 2 - 1) {
        cout << '-';
        x = 0;
        ++tmp;
      }
    }
    cout << '-';
    for (int i = len - 3; i < len; i++) {
      cout << num[i];
    }
    cout << endl;
  }
  return 0;
}
