# [Japt](https://github.com/ETHproductions/japt), 6 [bytes](https://en.wikipedia.org/wiki/ISO/IEC_8859-1)

    @øX}f1

[Try it](https://petershaggynoble.github.io/Japt-Interpreter/?v=1.4.6&code=QPhYfWYx&input=Wy01LCAtNCwgLTMsIC0yLCAtMSwgMCwgMSwgMiwgMywgNSwgNywgMTBd)

    @øX}f1     :Implicit input of array U
    @          :Function taking an integer X as argument
     øX        :  Does U contain X
       }       :End function
        f1     :Get the first integer >=1 that returns false