#include <bits/stdc++.h>
using namespace std;
int main() {
  int a;
  string s;
  cin >> a >> s;
  if (a % 2) {
    for (int i = 0; i < a - 4; i += 2) cout << s[i] << s[i + 1] << '-';
    cout << s[a - 3] << s[a - 2] << s[a - 1];
  } else {
    for (int i = 0; i < a - 3; i += 2) cout << s[i] << s[i + 1] << '-';
    cout << s[a - 2] << s[a - 1];
  }
  return 0;
}
