#include <bits/stdc++.h>
using namespace std;
void solve(string s, int n) {
  if (s.size() <= 3) {
    cout << s;
    return;
  }
  cout << s.substr(0, 2) << "-";
  s = s.substr(2, n - 2);
  solve(s, n);
}
int main() {
  int n;
  cin >> n;
  string s;
  cin >> s;
  solve(s, n);
}
