PPS Exam Ques -3 Alter

#include<stdio.h>

int main()
{
    long long int n,r,sum=0;
    int c=0,i,x,pow;
    scanf("%lld",&n);
again:
    r=n%10;
    n=n/10;
    if(r%2!=0)
    {
        if(c==0)
        {
            sum=sum+r;
            c++;
        }
        else
        {
            pow=1;
            for(i=0; i<c; i++)
            {
                pow=pow*10;
            }
            sum=sum+(r*pow);
            c++;
        }
    }
    if(n!=0)
    {
        goto again;
    }
    /** Prime Check **/
    for(i=1,x=0; i<=sum; i++)
    {
        if(sum%i==0)
        {
            x++;
        }
    }
    if(x<=2&&x>=1)
    {
        printf("\n\t%lld - Prime\n",sum);
    }
    else
    {
        printf("\t%lld - Not Prime\n",sum);
    }

return 0;
}