Untitled

namespace Rational
{
    class Rational
    {
        int num;
        int den;
        public Rational(Rational r)
        {
            this.num = r.num;
            this.den = r.den;
        }
        public Rational(int n, int d)
        {
            this.num = n;
            this.den = d;
            normalize();
        }
        public double getDec()
        {
            return (double)this.num / this.den;
        }
        
        public void multi(Rational r)
        {
            this.num *= r.num;
            this.den *= r.den;
            normalize();
        }
        public string print(){
            return string.Format("{0}/{1}", this.num, this.den);
        }
        
        public void dev(Rational r)
        {
            this.num *= r.den;
            this.den *= r.num;
            normalize();
        }
        
        public void add(Rational r)
        {
            this.num = (r.num*this.den)+(r.den*this.num);
            this.den *= r.den;
            normalize();
        }
        public void sub(Rational r)
        {
            this.num = (r.den * this.num) - (r.num * this.den);
            this.den *= r.den;
            normalize();
        }
        void normalize()
        {
            int a = Math.Abs(this.num);
            int b = Math.Abs(this.den);
           while (a != b)
            {
                if (a > b) a -= b;
                else b -= a;
            }
            this.num /= a;
            this.den /= a;
        }
    }

    class HelloWorld 
    {
        static void Main(string[] args)
    {
        Rational a = new Rational(4,10);
        Rational b = new Rational(4,5);
        Rational c = new Rational(a);
        Console.WriteLine(c.print());
        Console.WriteLine(c.getDec());
 
          
    }

    }
}