#include <bits/stdc++.h>
using namespace std;
long long read() {
  long long first = 0, f = 1;
  char ch = getchar();
  while (ch < '0' || ch > '9') {
    if (ch == '-') f = -1;
    ch = getchar();
  }
  while (ch >= '0' && ch <= '9') {
    first = first * 10 + ch - '0';
    ch = getchar();
  }
  return first * f;
}
template <class T>
inline void print(T first) {
  if (first < 0) putchar('-'), first = -first;
  register short a[20] = {}, sz = 0;
  while (first) a[sz++] = first % 10, first /= 10;
  if (sz == 0) putchar('0');
  for (int i = sz - 1; i >= 0; i--) putchar('0' + a[i]);
}
const long long inf = 2147483647;
const long long llinf = 2e18;
const int mod = 998244353;
const unsigned long long MAXMOD = (unsigned long long)mod * (mod - 1);
string s;
int main() {
  cin >> s;
  cin >> s;
  if (s.size() % 3 == 1) {
    cout << s[0] << s[1] << '-';
    s = s.substr(2);
  }
  for (int i = 0; i < s.size(); i++) {
    cout << s[i];
    if (i % 3 == 2 && i != s.size() - 1) cout << '-';
  }
  return 0;
}
