#include <iostream>
#include <fstream>
using namespace std;
ifstream fin("taxe.in");
ofstream fout("taxe.out");
long long s,a,st,dr,m,m2;
int main()
{
 fin>>a;
 a /=4;
 st=1;
 dr=a;
 while(st<=dr)
 {
    m=m2=(st+dr)/2;
    s=0;

    while (m2)
    {
        s+=m2;
        m2 /= 4;
    }
    if(s==a)
        break;
        else
        if(s<a)
        st=m+1;
    else
        dr=m-1;
 }
 fout<<m;
}