neighs_pcheck_all[]- the array contains all primitives more than once
int max_nm = max(neighs_pcheck_all) ;
for (int nm=0; nm<=max_nm; nm++)
{
        if (nm != @primnum)
        {
                found=0;
                foreach (int n; neighs_pcheck_all) 
                {
                        if (n == nm)
                        {
                                found++;
                        }
                }

                if (found>1 & found%2==0)
                {
                        append(neighs_prims ,nm);                }
        }
}

for (int nm=0; nm<=max_nm; nm++)

if (nm != @primnum)