A. Hmsh's calculator
time limit per test
1 s.
memory limit per test
256 MB
input
standard input
output
standard output

Ayham forgot his calculator before the exam, so he borrowed Hmsh's calculator from Qawasmeh. During the exam, he discovered that whenever he presses the add button, the calculator subtracts instead of adding.

Ayham needs to add two numbers $$$a$$$ and $$$b$$$ using the calculator. Help him to find the answer.

Input

The first and only line contains two integers $$$a$$$ and $$$b$$$ $$$(1 \le a, b \le 100)$$$.

Output

Output the result of adding the two numbers using Hmsh's calculator.

Examples
Input
5 3
Output
2
Input
1 1
Output
0
Input
1 2
Output
-1