Diana decided to do her Christmas shopping online this year, and all her presents have finally arrived! Since all the presents are already in boxes, Diana decides to just wrap them directly instead of unpacking them.

However, she now needs to figure out how much wrapping paper she needs for her presents. Given the dimensions of one of the boxes, can you figure out how much wrapping paper she would need to wrap the present?

Input

The input consists of one line containing three integers ~L, W, H~ ~(1 \le L, W, H \le 10^4)~, the dimensions of the box in centimetres.

Output

Output how many square centimetres of wrapping paper she needs to wrap the present.

Sample Input 1

2 3 4

Sample Output 1

52

Sample Input 2

3 1 2

Sample Output 2

22