#include <bits/stdc++.h>
using namespace std;
long long gcd(long long n, long long m) {
  long long x, y;
  if (n > m) {
    y = n;
    x = m;
  } else {
    y = m;
    x = n;
  }
  if (y % x == 0)
    return x;
  else {
    return gcd(x, y % x);
  }
}
int main() {
  long long n;
  cin >> n;
  string str;
  cin >> str;
  long long m = n;
  for (long long i = 0; i < n; i += 2) {
    if (m - 2 == 1) {
      cout << str[i] << str[i + 1] << str[i + 2];
      break;
    } else {
      cout << str[i] << str[i + 1];
      if (m - 2 != 0) cout << "-";
    }
    m -= 2;
  }
}
