struct Stack<T> {
    private var stack: [T]

    init()
    {
        stack = [T]()
    }

    mutating func push(val: T)
    {
        stack.append(val)
    }

    mutating func pop() -> T
    {
        return stack.removeLast()
    }

    var isEmpty: Bool {
        return stack.isEmpty
    }

    var count : Int {
        return stack.count
    }
}

// Int icin
var stackInt = Stack<Int>()

stackInt.push(val: 10)
stackInt.push(val: 20)
stackInt.push(val: 30)

while !stackInt.isEmpty {
    print(stackInt.pop())
}

// String Icin
var stackString = Stack<String>()

stackString.push(val: "Kerem")
stackString.push(val: "Swift")
stackString.push(val: "Python")

while !stackString.isEmpty {
    print(stackString.pop())
}