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