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();

		for (int i=1; i<=k; i++){
			if (a > b && a > c){
				a = a*2;
			} else if (b > c){
				b = b*2;
			} else {
				c = c*2;
			}
		}
		System.out.println(a+b+c);
	}

}

/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