#include <bits/stdc++.h>

using namespace std;
typedef unsigned long long ull;
int main()
{
    ull n;
    cin>>n;
    if(n==0)
    {
        cout<<0;
        return 0;
    }
    int cnt = 0;
    while(n!=0)
    {
        n = n&(n-1);
        cnt++;
    }
    ull k = 0;
    for(int i=0;i<cnt-1;i++)
    {
        k |= 1;
        k<<=1;
    }
    k |= 1;
    cout<<k;
    return 0;
}