#include<stdio.h>
int main()
{
    long long int n,a,b,c,d,e,rem;
    while(scanf("%lld",&n)!=EOF)
    {
        if(n==0)
        {
            break;
        }
        c=0;
        while(n>=3)
        {
            rem=n%3;
            a=rem;
            b=n/3;
            c=c+b;
            n=a+b;
        }
        d=c;
        if(n==2)
        {
            e=1;
            printf("%lld\n",d+e);
        }
        else
        {
            printf("%lld\n",d);
        }
    }
 
    return 0;
}