Identify errors in C# class implementation

What issues are present in the provided code? Will it compile successfully? If not — explain the reasons.

private sealed class Animal
    {
        private int Velocity = 150;

        void Run (int distance)
        {
            Velocity += distance;
        }
}

class Dog: Animal
    {
        Dog()
        {
            Velocity = 150;
        }

        void Run(int distance)
        {

        }
    }

public class Main
        {
            public Main()
            {
                var c = new Dog();
            }
}