#include <bits/stdc++.h>
using namespace std;
inline bool EQ(double a, double b) { return fabs(a - b) < 1e-9; }
template <typename T>
string to_str(T str) {
  stringstream stream;
  stream << str;
  return stream.str();
}
template <typename T>
int to_int(T num) {
  int val;
  stringstream stream;
  stream << num;
  stream >> val;
  return val;
}
vector<string> split(const string& s, char delim) {
  vector<string> elems;
  stringstream ss(s);
  string item;
  while (getline(ss, item, delim)) elems.push_back(item);
  return elems;
}
const int dr[] = {-1, -1, 0, 1, 1, 1, 0, -1};
const int dc[] = {0, 1, 1, 1, 0, -1, -1, -1};
int main() {
  int n;
  cin >> n;
  string s;
  cin >> s;
  if (n % 2 == 0) {
    cout << s[0] << s[1];
    for (int i = 2; i < n; i += 2) {
      cout << "-" << s[i] << s[i + 1];
    }
  } else {
    cout << s[0] << s[1] << s[2];
    for (int i = 3; i < n; i += 2) cout << "-" << s[i] << s[i + 1];
  }
  return 0;
}
