#include <iostream>
#include <string>
 
using namespace std;
 
bool isCommaOrSpace(char c)
{
   return c == ' ' || c == ',';
}
 
int main()
{
   string source = "   x  ,y  z  ,  a ,b, some text , ";
   string result = "";
   char last = ' ';
   for (unsigned int i=0; i<source.length(); i++)
   {
      if (source[i] != ' ' ||
          (!isCommaOrSpace(last) &&
           i < source.length()-1 && !isCommaOrSpace(source[i+1])))
      {
         result += source[i];
         last = source[i];
      }
   }
 
  cout << result << endl;
 
  int len;
  cin >> len;
  return 0;   
}
 

I2luY2x1ZGUgPGlvc3RyZWFtPgojaW5jbHVkZSA8c3RyaW5nPgoKdXNpbmcgbmFtZXNwYWNlIHN0ZDsKCmJvb2wgaXNDb21tYU9yU3BhY2UoY2hhciBjKQp7CiAgIHJldHVybiBjID09ICcgJyB8fCBjID09ICcsJzsKfQoKaW50IG1haW4oKQp7CiAgIHN0cmluZyBzb3VyY2UgPSAiICAgeCAgLHkgIHogICwgIGEgLGIsIHNvbWUgdGV4dCAsICI7CiAgIHN0cmluZyByZXN1bHQgPSAiIjsKICAgY2hhciBsYXN0ID0gJyAnOwogICBmb3IgKHVuc2lnbmVkIGludCBpPTA7IGk8c291cmNlLmxlbmd0aCgpOyBpKyspCiAgIHsKICAgICAgaWYgKHNvdXJjZVtpXSAhPSAnICcgfHwKICAgICAgICAgICghaXNDb21tYU9yU3BhY2UobGFzdCkgJiYKICAgICAgICAgICBpIDwgc291cmNlLmxlbmd0aCgpLTEgJiYgIWlzQ29tbWFPclNwYWNlKHNvdXJjZVtpKzFdKSkpCiAgICAgIHsKICAgICAgICAgcmVzdWx0ICs9IHNvdXJjZVtpXTsKICAgICAgICAgbGFzdCA9IHNvdXJjZVtpXTsKICAgICAgfQogICB9CgogIGNvdXQgPDwgcmVzdWx0IDw8IGVuZGw7CgogIGludCBsZW47CiAgY2luID4+IGxlbjsKICByZXR1cm4gMDsgICAKfQo=