import java.util.Scanner;
class Main{
    public static void main(String arg[]){
        Scanner scn=new Scanner(System.in);
        int[] num= new int[3];
        int max = 0;
        int maxNum = 0;
        for(int i=0;i<3;i++){
            num[i]=scn.nextInt();
            if(max<num[i]){
                max = num[i];
                maxNum=i;
            }
        }
        int k = scn.nextInt();
        int answer = 0;
        for(int i=0;i<3;i++){
            if(maxNum==i){
                max *= Math.pow(2,k);
                answer += max;
            }else{
                answer+=num[i];
            }
        }
        System.out.println(answer);
    }
}
/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