Олимпиадный тренинг

Задача 27059. Formula - 5


Write a program that calculates the value of y.
\(y = \frac {a + b} {2}\)


Input
The input is 2 integers and b.

Imprint
Print the value y.
 
Examples
# Input Output
1 2 2 2
2 1 2 1.5