#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, i, j;
  char str[105];
  cin >> n;
  cin >> str;
  i = 0;
  while (i < n - 1) {
    if ((n - 1) - (i) == 2) {
      cout << str[i] << str[i + 1] << str[i + 2];
      i = i + 3;
    } else {
      cout << str[i] << str[i + 1];
      i = i + 2;
    }
    if (i < n - 1) cout << "-";
  }
  return 0;
}
