# [05AB1E], 4 bytes

    ±1^±

Explanation:

       ±      Bitwise NOT
    ±           Bitwise NOT (implicit) input
      ^         XOR
     1          one


[Try it online!]

[05AB1E]: https://github.com/Adriandmen/05AB1E
[Try it online!]: https://tio.run/nexus/05ab1e#@39oo2HcoY3//5sBAA "05AB1E – TIO Nexus"