#include <bits/stdc++.h>
using namespace std;
string s[55];
int main() {
  int n;
  cin >> n;
  string s;
  cin >> s;
  if (n % 2 == 0) {
    printf("%c%c", s[0], s[1]);
    for (int i = 2; i < n; i += 2) {
      printf("-%c%c", s[i], s[i + 1]);
    }
  } else {
    printf("%c%c%c", s[0], s[1], s[2]);
    for (int i = 3; i < n; i += 2) {
      printf("-%c%c", s[i], s[i + 1]);
    }
  }
}
