import java.util.*;

public class Main{
  public static void main(String[]args){
    Scanner sc = new Scanner(System.in);
    int A = Integer.parseInt(sc.next());
    int B = Integer.parseInt(sc.next());
    int C = Integer.parseInt(sc.next());
    int K = Integer.parseInt(sc.next());
    
    int a = A;
    int b = B;
    int c = C;
    for(int i = 0; i < K; i++){
      a *= 2;
      b *= 2;
      c *= 2;
    }
    
    System.out.println(Math.max(a+B+C, Math.max(A+b+C, 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