using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace WindowsFormsApplication1
{
    class BigInteger
    {
        int[] value = new int[200];

        private BigInteger()
        {

        }
        public BigInteger(String a)
        {
            var tmp = a.ToCharArray();
            for (int i = tmp.Length - 1, j = value.Length - 1; i >= 0 && j >= 1; i--, j--)
            {
                int buf;
                value[0] = 0;
                if (int.TryParse(Convert.ToString(tmp[i]), out buf) == true)
                {
                    value[j] = buf;
                }
                else
                {

                }
            }
            if (tmp[0] == '-')
            {
                //Console.WriteLine("go");
                value = toComp(value);
                //value[0] = 9;
            }
        }
        public BigInteger add(BigInteger a)
        {
            BigInteger result = new BigInteger();
            if (a.value[0] == 9)
            {
                BigInteger b = new BigInteger();
                b.value = toComp(a.value);
                return sub(b);
            }
            else
            {
                int carry = 0;
                for (int i = value.Length - 1; i >= 0; i--)
                {
                    result.value[i] = value[i] + a.value[i] + carry;
                    if (result.value[i] < 10)
                    {
                        carry = 0;
                    }
                    else
                    {
                        result.value[i] %= 10;
                        carry = 1;
                    }
                }
            }

            return result;
        }

        public BigInteger sub(BigInteger a)
        {
            BigInteger result = new BigInteger();
            //Console.WriteLine(String.Concat(a.value));
            if (a.value[0] == 9)
            {
                BigInteger b = new BigInteger();
                b.value = toComp(a.value);
                return add(b);
            }
            else
            {
                int borrow = 0;
                for (int i = value.Length - 1; i >= 0; i--)
                {
                    result.value[i] = value[i] - a.value[i] - borrow;
                    if (result.value[i] >= 0)
                    {
                        borrow = 0;
                    }
                    else
                    {
                        result.value[i] += 10;
                        borrow = 1;
                    }
                }
            }
            return result;
        }

        public int[] toComp(int[] a)
        {
            //BigInteger b = new BigInteger();
            int[] b = new int[200];
            for (int i = 0; i < 200; i++)
            {
                b[i] = 9 - a[i];
            }
            b[200 - 1] += 1;
            //BigInteger tmp = new BigInteger("1");
            //b.add(tmp);

            //Console.WriteLine(String.Concat(b));
            return b;
        }
        public static BigInteger operator +(BigInteger a, BigInteger b)
        {
            return a.add(b);
        }
        public static BigInteger operator -(BigInteger a, BigInteger b)
        {
            return a.sub(b);
        }
        public override string ToString()
        {
            string output = "";
            int zeroCheck = 0, check = 0;
            if (value[0] == 9)
            {
                value = toComp(value);
                output = "-";
            }
            for (int i = 1; i < value.Length; i++)
            {
                if (value[i] != 0)
                {
                    zeroCheck = 1;
                }
                if (zeroCheck == 1)
                {
                    output = String.Concat(output, value[i]);
                    check = 1;
                }
            }
            if (check == 0)
            {
                output = String.Concat(output, 0);
            }
            return output;
        }


    }
}