import java.util.*;
public class Main {
public static void main(String[] args){
Scanner sc = new Scanner(System.in);
int[] v=new int[3];
v[0]=Integer.parseInt(sc.next());
v[1]=Integer.parseInt(sc.next());
v[2]=Integer.parseInt(sc.next());
int K=Integer.parseInt(sc.next());
Arrays.sort(v);
for(int i=0;i<K;i++){
v[2]*=2;
}
System.out.println(v[0]+v[1]+v[2]);
}}
/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