using System;

        class Rational

        {

            public int num;

            public int denum;

            public double dec;

            public void Add(Rational r)

            {

                this.num = this.num * r.denum + r.num * this.denum;

                this.denum = this.denum * r.denum;

​

            }

            public void Sub(Rational r)

            {

                this.num = this.num * r.denum - r.num * this.denum;

                this.denum = this.denum * r.denum;

            }

            public void Mult(Rational r)

            {

                this.num = this.num * r.num;

                this.denum = this.denum * r.denum;

            }

            public void Div(Rational r)

            {

                this.num = this.num * r.denum + r.num;

                this.denum = this.denum * r.num;

            }

        public int Compare(Rational r)

        {

            if (this.num * r.denum > r.num * this.denum)

            {

                return 1;

            }

            if (this.num * r.denum < r.num * this.denum)

            {

                return -1;

            }

            return 0;

        }

                public void Dec()

                {

                    this.dec = (double)this.num / this.denum;

                }

                public void Print()

                {

                    Console.WriteLine("{0}/{1} = {2}", this.num, this.denum, this.dec);

                }

   }

   public class Program

    {

        public static void Main()

        {

            Rational rc = new Rational();

            rc.num = 1;rc.denum = 2;

            rc.Dec(); rc.Print();

            Rational rc2 = new Rational();

            rc2.num = 2;rc2.denum = 3;

            rc2.Dec(); rc2.Print();

            rc2.Add(rc);rc2.Dec();rc2.Print();

            rc2.Sub(rc);rc2.Dec();rc2.Print();

            rc2.Mult(rc);rc2.Dec();rc2.Print();

            Console.WriteLine(rc.Compare(rc2));

         }

}

​