Competitions

# Виток 1, Шаг 8 - Битовые операции

# Invert a bit

Two integers **а** and **k** are given. Print number that is obtained from **а** by inverting the **k**-th bit.

#### Input

One line contains two integers **a** and **k** (**0** ≤ **a** ≤ `10`

).^{9}

#### Output

Print the number **a** with **k**-th bit inverted.

Input example #1

5 1

Output example #1

7