
import java.util.Scanner;

public class Main{

	public static void main(String args[]){

		Scanner sc = new Scanner(System.in);
		int a = sc.nextInt();
		int b = sc.nextInt();
		int c = sc.nextInt();
		int k = sc.nextInt();
		int result = 0;
		
		int m = Math.max(a, b);
		int max =Math.max(m, c);
		int maxt = max;
				
		for(int i = 0; i < k; i ++) {
			max *= 2;
		}
		
		result = max + a + b + c - maxt;
		
		System.out.println(result);
	}
}

/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