uva 11877 cola store

#include<stdio.h>
int main()
{
    long long N,n,a,b,c,d,e,f,g,h,i,j,k,l,m,o,p,q,r,sum;
    while(scanf("%lld",&N)==1)


    {
        if(N==0)
        {
            break;
        }
        n=N;

        a=n%3;
        if(a==0)
            b=n+1;
            if(a==1)
                b=n+1;
        if(a==2)
            b=n+1;
        c=b/3;
        d=b%3;
        e=c+d;
        f=e/3;
        g=e%3;
        h=f+g;
        i=h/3;
        j=h%3;
        k=i+j;
        l=k/3;
        m=k%3;
        r=l+m;
        o=r/3;
        p=r%3;
        q=o+p;
        sum=c+f+i+l+o;
        if(a==1)
            sum=sum;
        if(a==2)
            sum=sum;
        printf("%lld\n",sum);



    }

    return 0;
}