#include<bits/stdc++.h>
using namespace std;
int n,ans;
int f(int x,int y)
{
    if(x<3) return x;
    y+=x%3;
    return x+f((x+y)/3,(x+y)%3);
}
int main()
{
    cin>>n;
    int l=1,r=n;
    while(l<=r)
    {
        int mid=(l+r)/2;
        if(f(mid,0)>=n)
        {
          ans=mid;
          r=mid-1;
        }
        else
        {
          l=mid+1;
        }
    }
    cout<<ans;
}