#import system.
#import extensions.

#symbol program =
[
    #var s := "0123456789".
    #var n := 3.
    #var m := 2.
    #var c := #51.
    #var z := "345".

    console writeLine:(s Substring:m &at:n).
    console writeLine:(s Substring:(s length - n) &at:n).
    console writeLine:(s Substring:(s length - 1) &at:0).
    console writeLine:(s Substring:m &at:(s indexOf:c &at:0)).
    console writeLine:(s Substring:m &at:(s indexOf:z &at:0)).
].