Alice has a right angled triangle with integer side lengths. Given the lengths of the three sides of the triangle, find the area of the triangle.
The first line will contain ~3~ integers, ~a, b, c~ ~(1 \le a, b, c \le 2~ ~000)~, the three side lengths of the triangle.
It is guaranteed that the side lengths will form a valid right angle triangle.
Output the area of the triangle, rounded to the nearest integer.
Sample Input 1
12 13 5
Sample Output 1
Sample Input 2
25 24 7
Sample Output 2