    package org.example

    fun main(args: Array<String>) {
        val sum1 = add(5, 6)
        println(sum1)
        println("""
    $$a${1+2}\$$
    abc
    """)
    }

    /**
    * add function with two, three or four integer arguments
    * c : default argument is 0
    * d : default argument is 0
    */
    fun add(a:Int, b:Int, c:Int = 0, d:Float = 12e10F): Int {
        return a + b + c + d
    }