class Tree
    {
        private TreeNode Root;

        public void Destroy()
        {
            Root = new TreeNode();
        }

        public Tree()
        {
            Root = new TreeNode();
        }

        #region CreateTree(int[],int)

        private bool FindNotZero(int[] Mas)
        {
            bool result= false;
            int summa=0;
            for (var i = 0; i < Mas.Length; i++) summa += Mas[i];
            if (summa > 0) result = true;
            return result;
        }


        public void CreateTree(int[] Mas,int result)
        {
            TreeNode root=Root;
            Random rnd = new Random();
            bool res = false;
            int i = 0;
            int kof = 1;
            int element;
            int Result=result/2;
            if (result % 2 != 0) Result++;
            if ((Mas[2] == 0) && (Mas[3] == 0))
            {
                Result = result;
            }
            if ((Mas[0] == 0) && (Mas[1] == 0))
            {
                Result = result;
            }
            while (FindNotZero(Mas))
            {
                res = false;

                while (res!=true)
                {
                    if ((Mas[2] != 0) || (Mas[3] != 0)) i = rnd.Next(2, 4);
                    else i = rnd.Next(0, 2);
                    if (Mas[i] != 0) res = true;
                }

                switch (i)
                {
                    case 0:
                        Mas[i]--;

                        if (Root.RightNode == null)
                        {
                            if(Root.LeftNode!=null)Result = result / 2;
                            Root.RightNode = new TreeNode(Result);
                        }

                        root = Root.RightNode;
                        while (root.LeftNode != null) root = root.LeftNode;
                        root.LeftNode = new TreeNode('+');
                        root = root.LeftNode;
                        if(Result+1>0)element = rnd.Next(0, Result+1);
                        else element = rnd.Next( Result + 1,0);
                        root.LeftNode = new TreeNode(element);
                        root.RightNode = new TreeNode(Result - element);
                        //if ((Mas[i] == 0)&&(root.LeftNode.Figure>=0)) root.LeftNode.Sign = 'm';
                        Result = element;
                        break;

                    case 1:
                        Mas[i]--;

                        if (Root.RightNode == null)
                        {
                            if (Root.LeftNode!= null) Result = result / 2;
                            Root.RightNode = new TreeNode(Result);
                        }

                        root = Root.RightNode;
                        while (root.LeftNode != null) root = root.LeftNode;

                        root.LeftNode = new TreeNode('-');
                        root = root.LeftNode;

                        element = rnd.Next(Result - 1, Result + Result / 100 * 20);
                        root.LeftNode = new TreeNode(element);
                        root.RightNode = new TreeNode(element - Result);
                        //if ((Mas[i] == 0) && (root.LeftNode.Figure >= 0)) root.LeftNode.Sign = 'm';
                        Result = element;
                        break;

                    case 2:
                        Mas[i]--;

                        root = Root;
                        while (root.LeftNode != null) root=root.LeftNode;
                        root.LeftNode = new TreeNode('/');
                        root = root.LeftNode;

                        kof = 1;
                        element = rnd.Next(Result, Result +Result+200);

                        while ((element % kof != 0) || (element / kof != Result))
                        {
                            if ((kof > element)||(element/kof<Result))
                            {
                                element = rnd.Next(Result, Result + Result+200);
                                kof = 1;
                            }
                            kof++;
                        }


                         root.LeftNode = new TreeNode(element);
                         root.RightNode = new TreeNode(kof);

                         Result = element;


                        break;

                    case 3:
                        Mas[i]--;

                        root = Root;
                        while (root.LeftNode != null) root = root.LeftNode;
                        root.LeftNode = new TreeNode('*');
                        root = root.LeftNode;


                        kof = 1;
                        element = rnd.Next(1, Result+1);

                        while((element*kof!=Result))
                        {
                            kof++;
                            if (kof * element > Result)
                            {
                                element = rnd.Next(1, Result+1);
                                kof = 1;
                            }
                        }

                        if (kof>element)
                        {
                            root.LeftNode = new TreeNode(kof);
                            root.RightNode = new TreeNode(element);
                            Result = kof;
                        }
                        else
                        {
                            root.LeftNode = new TreeNode(element);
                            root.RightNode = new TreeNode(kof);
                            Result = element;
                        }

                        break;
                }

            }
        }

        #endregion

        #region Строка


        private string RowProcess(StringBuilder str)
        {
            var i=0;
            while (i<str.Length)
            {
                if (((int)str[i] == 0) && (i + 1 < str.Length) && (i != 0))
                {
                    if (str[i + 1] != '-') str[i] = '+';
                    else str.Remove(i, 1);
                }
                else
                if ((str[i] == '-') && (str[i + 1] == '-'))
                {
                    str[i] = '+';
                    str.Remove(i + 1, 1);
                }
                else if (str[i] == '+' && str[i + 1] == '-') str.Remove(i, 1);
                else if (str[i] == '-' && str[i + 1] == '+') str.Remove(i+1, 1);


                i++;
            }
            return Convert.ToString(str);
        }

        private StringBuilder ToString(TreeNode root)
        {
            StringBuilder str = new StringBuilder("");
            if (root != null)
            {
                if (root.LeftNode != null) str.Insert(str.Length, ToString(root.LeftNode));

                if (root.Sign != 'e') str.Insert(str.Length, root.Sign);
                else
                {
                    if (((root.LeftNode != null) && (root.RightNode == null)) || ((root.LeftNode == null) && (root.RightNode != null))) ;
                    else str.Insert(str.Length, root.Figure);
                }

                if (root.RightNode != null) str.Insert(str.Length, ToString(root.RightNode));
            }
            return str;
        }

        #endregion

        public string Generate(int pCount, int sCount, int dCount, int mCount, int result)
        {
            Destroy();
            Root.Figure = result;
            int[] Mas = new int[4] { pCount, sCount, dCount, mCount };
            CreateTree(Mas,result);
            string str = RowProcess(ToString(Root));
           // Console.WriteLine((int)str[4]);
            return str;
        }