#include <bits/stdc++.h>
using namespace std;
int main() {
  int a, b, c, d, i, j, k, l, e;
  char n[105];
  while (~scanf("%d", &a)) {
    getchar();
    for (i = 1; i <= a; i++) scanf("%c", &n[i]);
    d = a;
    e = 0;
    for (j = 1; j <= a; j++) {
      if (d % 2 == 0) break;
      printf("%c", n[j]);
      if (j % 3 == 0 && j != 0 & j != a) {
        printf("-");
        d -= 3;
      }
    }
    for (k = j; k <= a; k++) {
      e += 1;
      printf("%c", n[k]);
      if (e % 2 == 0 && k != a) printf("-");
    }
    printf("\n");
  }
}
