3 open class A(n: Int, <bold>s: String = "???"</bold>)
3 	open class A(n: Int, s: String = <bold>"???"</bold>)
6 	class B2: A(1, <bold>"2"</bold>)
7 	class B3: A(1, s = <bold>"2"</bold>)
8 	class B4: A(n = 1, s = <bold>"2"</bold>)
9 	class B5: A(s = <bold>"2"</bold>, n = 1)
13 	A(1, <bold>"2"</bold>)
14 	A(1, s = <bold>"2"</bold>)
15 	A(n = 1, s = <bold>"2"</bold>)
16 	A(s = <bold>"2"</bold>, n = 1)
