Week 1 Introduction Part 2

Find the number

Time limit 1 second
Memory limit 128 MiB

Find the integer value of n, if its previous and next numbers are known.

Input data

Two integers - the previous and the next number for n, given in any order in one line, space separated. The numbers do not exceed 10^9 by absolute value.

Output data

Print the value of n.


Input example #1
6 8
Output example #1
Input example #2
-16 -18
Output example #2
Author Matviychuk Sergiy
Source "ABC programming"