#include <bits/stdc++.h>
using namespace std;
template <typename T>
void print1d(vector<T> &a) {
  for (long long int i = 0; i < a.size(); i++) {
    cout << a[i] << " ";
  }
  cout << endl;
}
vector<long long int> divisor(long long int n) {
  vector<long long int> a;
  for (long long int i = 1; i * i <= n; i++) {
    if (n % i == 0) {
      if (n / i == i)
        a.push_back(i);
      else {
        a.push_back(i);
        a.push_back(n / i);
      }
    }
  }
  return a;
}
bool sortsecond(const pair<long long int, long long int> &a,
                const pair<long long int, long long int> &b) {
  return a.second < b.second;
}
bool isPrime(long long int n) {
  for (long long int i = 2; i * i <= n; i++) {
    if (n % i == 0) return false;
  }
  return true;
}
vector<string> split_string(const string &s, const string &delimiter) {
  vector<string> token;
  string ans;
  size_t end_point, start_point = 0, delim_length = delimiter.length();
  while ((end_point = s.find(delimiter, start_point)) != string::npos) {
    ans = s.substr(start_point, end_point - start_point);
    start_point = end_point + delim_length;
    token.push_back(ans);
  }
  token.push_back(s.substr(start_point));
  return token;
}
bool is_vowel(const char &a) {
  switch (a) {
    case 'a':
    case 'e':
    case 'i':
    case 'o':
    case 'u':
    case 'y':
    case 'A':
    case 'E':
    case 'I':
    case 'O':
    case 'U':
      return true;
      break;
    default:
      return false;
      break;
  }
}
void solve() {
  string delimiter = ",";
  string s;
  cin >> s;
  vector<string> e = split_string(s, delimiter);
  vector<long long int> a(e.size(), 0);
  for (long long int i = 0; i < e.size(); i++) {
    a[i] = stoi(e[i]);
  }
  sort(a.begin(), a.end());
  auto it = std::unique(a.begin(), a.end());
  a.resize(std::distance(a.begin(), it));
  long long int c = a[0], k = a[0] + 1;
  for (long long int i = 1; i < a.size(); i++) {
    if (a[i] == k)
      k++;
    else {
      if (c + 1 == k)
        cout << c << ",";
      else
        cout << c << "-" << k - 1 << ",";
      c = a[i];
      k = a[i] + 1;
    }
  }
  if (c + 1 == k)
    cout << c << endl;
  else
    cout << c << "-" << k - 1 << endl;
}
int32_t main() {
  ios_base::sync_with_stdio(false), cin.tie(0), cout.tie(0);
  ;
  solve();
  return 0;
}
