using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Net.Sockets;
using System.Reflection.Emit;


namespace MyApp
{
    ///****************************(Classes)********************************/
    class polyNode
    {
        public int coff;
        public int ex;
        public polyNode next;

        public polyNode(int co, int e)
        {
            next = null;
            coff = co;
            ex = e;
        }
    }

    class Polynomial
    {
        public polyNode head;

        public void add_term(int coff, int exp)
        {
            polyNode p = new polyNode(coff, exp);
            if (head == null || head.ex < exp)
            {
                p.next = head;
                head = p;
                return;
            }
            polyNode tmp = head;
            while(tmp.next != null && tmp.next.ex > exp)
            {
                tmp = tmp.next;
            }
            if(tmp.next != null && tmp.next.ex == exp) 
            {
                tmp.next.coff += coff;
                return;
            }
            p.next = tmp.next;
            tmp.next = p;
        }
    }

    class Add
    {
        private Polynomial result = new Polynomial();

        public Add(Polynomial p1, Polynomial p2)
        {
            polyNode tmp1 = p1.head , tmp2 = p2.head;
            while (tmp1 != null || tmp2 != null)
            {
                if (tmp1 == null)
                {
                    result.add_term(tmp2.coff, tmp2.ex);
                    tmp2 = tmp2.next;
                }
                else if (tmp2 == null)
                {
                    result.add_term(tmp1.coff, tmp1.ex);
                    tmp1 = tmp1.next;
                }
                else if (tmp1.ex == tmp2.ex)
                {
                    int ncoff = tmp1.coff + tmp2.coff;
                    result.add_term(ncoff, tmp1.ex);
                    tmp1 = tmp1.next;
                    tmp2 = tmp2.next;
                }
                else if (tmp1.ex > tmp2.ex)
                {
                    result.add_term(tmp1.coff, tmp1.ex);
                    tmp1 = tmp1.next;
                }
                else
                {
                    result.add_term(tmp2.coff, tmp2.ex);
                    tmp2 = tmp2.next;

                }
            }
        }

        public void display()
        {
            polyNode tmp = result.head;
            if (tmp == null)
            {
                Console.WriteLine("Empty");
                return;
            }
            while (tmp != null)
            {
                Console.Write("{0}x^{1} ", tmp.coff, tmp.ex);
                tmp = tmp.next;
                if (tmp != null)
                {
                    Console.Write("+ ");
                }
            }
        }
    }
    /********************************************************************/
    internal class Program
    {

        ///-----------------------(funcoins )--------------------------------/


        //------------------------------------------------------------------------/

        static void Main()
        {
            Polynomial p1 = new Polynomial();
            p1.add_term(2, 3);
            p1.add_term(3, 2);
            p1.add_term(4, 1);
            Polynomial p2 = new Polynomial();
            p2.add_term(2, 0);
            p2.add_term(3, 5);
            p2.add_term(7, 1);
            Add add = new Add(p1, p2);
            add.display();
        }

    }
}