def remove(self, key):
        node = self.tree
        nodePar = None
        #finding node with the key and its parent
        while (node != None):
            if node.key == key:
                break
            elif node.key < key:
                if node.right != None:
                    if node.right.key ==key:
                        nodePar = node
                node = node.right
            else:
                if node.left!=None:
                    if node.left.key ==key:
                        nodePar = node
                node = node.left
        if node == None:
             return False

        if node.right == None:
            if nodePar != None:
                if node.key>nodePar.key:
                    nodePar.right = node.left
                else:
                    nodePar.left = node.left
            else:
                self.tree = node.left

        elif node.left == None:
            if nodePar != None:
                if node.key>nodePar.key:
                    nodePar.right = node.right
                else:
                    nodePar.left = node.right
            else:
                self.tree = node.right
        elif node.left!=None and node.right!=None:
            toExchange = node.right
            par = None
            while toExchange.left!=None:
                par = toExchange
                toExchange = toExchange.left
            node.value = toExchange.value
            node.key = toExchange.key
            if par!=None:
                par.left = toExchange.right
            if par == None:
                node.right = toExchange.right