Complex

struct complex
    {
        public float real;
        public float imaginary;

        public complex(float real, float imaginary)
        {
            this.real = real;
            this.imaginary = imaginary;
        }

        public static complex operator +(complex a, complex b)
        {
            return new complex(a.real + b.real, a.imaginary + b.imaginary);
        }
        public static complex operator -(complex a, complex b)
        {
            return new complex(a.real - b.real, a.imaginary - b.imaginary);
        }

        public override string ToString()
        {
            return (String.Format("{0} + {1}i", real, imaginary));
        }
    }

    class Program
    {
        static void Main(string[] args)
        {
            complex c1 = new complex(3.0f, 5.0f);
            complex c2 = new complex(2.5f, 3.0f);

            complex c = c1 + c2;
            Console.WriteLine("Sum = {0}", c);
            Console.ReadLine();
        }
    }