Expressions are not allowed at the top level ERROR

import Foundation

class BlogPost {
    var title = "";
    var body = "";
    var author = "";
    var numberOfComments = 0;

    func addComment() {
        numberOfComments += 1;
    }
}

let firstPost = BlogPost();
firstPost.title = "Hello Classes!";
firstPost.author = "Joseph Frazer";
firstPost.body = "Hello";
firstPost.addComment();

let secondPost = BlogPost();
firstPost.title = "Goodbye Classes!";
firstPost.author = "Joseph Frazer";
firstPost.body = "Hello";

print(firstPost.numberOfComments);
print(secondPost.numberOfComments);

// Inheritance

class Car {
    var topSpeed = 200;

    func drive() {
        print("Driving at /(topspeed)");
    }
}

class Futurecar : Car {
    func fly() {
        print("Flying");
    }
}

let myRide = Car();
myRide.topSpeed;
myRide.ride();