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import kotlin.math.*
import kotlin.test.*

fun main() { 
   //sampleStart 
   val list = mutableListOf('a', 'b', 'c')
println("list.add('c') is ${list.add('c')}") // true
println(list) // [a, b, c, c] 
   //sampleEnd
}

import kotlin.math.*
import kotlin.test.*

fun main() { 
   //sampleStart 
   val set = mutableSetOf('a', 'b', 'c')
// Sets do not support duplicates, so there is no way to add yet another 'c'
println("set.add('c') is ${set.add('c')}") // false
println(set) // [a, b, c] 
   //sampleEnd
}