using System;

public class Hello
{
    static void Main()
    {
        var n = long.Parse(Console.ReadLine().Trim());
        getAns(n);
    }
    static bool check1(long n, long t)
    {
        var sum = t;
        if (sum == n) { return true; }
        while (true)
        {
            t /= 2;
            sum += t;
            if (sum == n) { return true; }
            if (t == 1) break;
        }
        return false;
    }
    static bool check0(long n, long t)
    {
        var sum = t;
        while (true)
        {
            t /= 2;
            sum += t;
            if (t == 1) break;
        }
        return sum >= n;
    }
    static long getNum(long n)
    {
        var ok = n;
        var ng = 1L;
        while (ok - ng > 1)
        {
            var mid = ng + (ok - ng) / 2;
            if (check0(n, mid)) ok = mid;
            else ng = mid;
        }
        return ok;
    }
    static void getAns(long n)
    {
        var c = getNum(n);
        for (long i = c; i <= n; i++)
        {
            if (check1(n, i)) { Console.WriteLine(i); return; }
        }
    }
}