import java.util.Scanner;

public class Main {
  public static void main (String[] args) {
    Scanner in = new Scanner(System.in);

    while (in.hasNext()) {
      int A = in.nextInt();
      int B = in.nextInt();
      int C = in.nextInt();
      int K = in.nextInt();
      long max = Math.max(A, Math.max(B, C));
      long replacedMax = max;

      while (K-- > 0){
        replacedMax *= 2;
      }
  
      System.out.println(replacedMax + A + B + C - max);
    }
  }
}
/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