There are three positive integers A, B and C written on a blackboard. E869120 performs the following operation K times:
- Choose one integer written on the blackboard and let the chosen integer be n. Replace the chosen integer with 2n.
What is the largest possible sum of the integers written on the blackboard after K operations?

-----Constraints-----
- A, B and C are integers between 1 and 50 (inclusive).
- K is an integer between 1 and 10 (inclusive).

-----Input-----
Input is given from Standard Input in the following format:
A B C
K

-----Output-----
Print the largest possible sum of the integers written on the blackboard after K operations by E869220.

-----Sample Input-----
5 3 11
1

-----Sample Output-----
30

In this sample, 5, 3, 11 are initially written on the blackboard, and E869120 can perform the operation once.

There are three choices:
- Double 5: The integers written on the board after the operation are 10, 3, 11.
- Double 3: The integers written on the board after the operation are 5, 6, 11.
- Double 11: The integers written on the board after the operation are 5, 3, 22.
If he chooses 3., the sum of the integers written on the board afterwards is 5 + 3 + 22 = 30, which is the largest among 1. through 3.

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