#include <bits/stdc++.h>
using namespace std;
int a[10000];
int main() {
  int n;
  int flag;
  char s[1000];
  while (~scanf("%d", &n)) {
    getchar();
    gets(s);
    int len = strlen(s);
    if (len % 2 == 0) {
      for (int i = 0; i < len; i++) {
        if ((i + 1) % 2 == 0 && i != len - 1)
          printf("%c-", s[i]);
        else
          printf("%c", s[i]);
      }
      printf("\n");
      continue;
    } else {
      for (int i = 0; i < len - 3; i++) {
        if ((i + 1) % 2 == 0 && i != len - 1)
          printf("%c-", s[i]);
        else
          printf("%c", s[i]);
      }
      for (int i = len - 3; i < len; i++) printf("%c", s[i]);
      printf("\n");
      continue;
    }
  }
  return 0;
}
