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#Python 3
a=input()
a=int(a)
b=a
while a>0:
    b+=a//3
    a/=3
print(int(b))

//cpp
#include<bits/stdc++.h>
using namespace std;
int main(){
    int a,sum=0;
    cin>>a;
    while(a>0){
        sum+=a/3;
        a/=3;
    }
    cout<<a;
}