#include <bits/stdc++.h>
const int MAXN = 100;
int N;
char chaine[MAXN + 1];
int main() {
  scanf("%d%s", &N, chaine);
  if (N % 2 == 0) {
    for (int i = 0; i < N - 2; i += 2)
      printf("%c%c-", chaine[i], chaine[i + 1]);
    printf("%c%c\n", chaine[N - 2], chaine[N - 1]);
  } else {
    for (int i = 0; i < N - 3; i += 2)
      printf("%c%c-", chaine[i], chaine[i + 1]);
    printf("%c%c%c\n", chaine[N - 3], chaine[N - 2], chaine[N - 1]);
  }
  return 0;
}
