import java.util.*;
import java.util.ArrayDeque;
import java.util.Queue;
import java.math.RoundingMode;
import java.math.BigDecimal;
 
 
 
public class Main{
	 public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
		long H = sc.nextLong();
		long ans = 1;
			for(int i = 1; i < 41; i++) {
				long right = 1;
				long left = 1;
				for(int j = 0; j < i-1; j++) {
					left*=2;
				}
				for(int j = 0; j < i; j++) {
					right*=2;
				}
				if(left<=H&&H<right) {
					ans = right-1;
					break;
				}
			}
		System.out.println(ans);
	 }
}
/tmp/hf-datasets-cache/medium/datasets/42704881117311-config-parquet-and-info-qiankunmu-Project_CodeNet-896c9d36/hub/datasets--qiankunmu--Project_CodeNet_Python800_and_Java250/snapshots/c899fde44a77ba1cc14973ed3de064e4ff3aadc7/Project_CodeNet_Java250.tar.gz