#include <bits/stdc++.h>
using namespace std;
long long int i = 0, j = 0, k = 0;
void solve() {
  int n;
  cin >> n;
  string s;
  cin >> s;
  if (n % 2 == 0) {
    for (i = 0; i < n - 1; i += 2) {
      cout << s[i] << s[i + 1];
      if (i != n - 2) cout << "-";
    }
  } else {
    for (i = 0; i < n - 3; i += 2) cout << s[i] << s[i + 1] << "-";
    cout << s[n - 3] << s[n - 2] << s[n - 1];
  }
}
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  int t = 1;
  while (t--) solve();
}
