import Cocoa

var str = "Hello, playground"

protocol FirstName {
    var firstName: String { get set }

    func result() -> String
}

protocol Person: FirstName {
    var age: Int { get }
}

struct Student: Person {
    var age: Int

    var firstName: String

    func result() -> String {
        return firstName + " age: " + String(age)
    }
}

func checking(check: FirstName) {
    print(check.firstName)
}

var kek = Student(age: 30, firstName: "name")
kek.age = 14

var huek: Person = kek
huek.age = 88