Dobar broj (maksimalan do n)

#include <iostream>
using namespace std;

bool dobarbroj (int n)
{
     int a, s=0; bool p;

     a = n;
     p = true;
     while (a>10)
     {
         s = s + a%10;
         if (a/10%10 <= s)
         p = false;
         a = a / 10;
     }
     return p;
}

main()
{
      int n, max = 0;

      while (n!=0)
      {
            cin >> n;
            if ((dobarbroj(n)==true)&&(n>max))
            max = n;
      }

      if (max == 0)
      cout << "Ne postoji takav broj! " << endl;
      else
      cout << max << endl;

      system ("PAUSE");
}