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