write a python code of 1- One-Way linked list 2- First node will have the count of the number of nodes available in the linked list (excluding the first node), initially the linked list will have 1 node with value 0 indicating zero nodes. 3- The linked list will contain a mathematical expression given by the user during run-time. 4- The program must do the following o Check the input expression for Brackets/Parenthesis checking. o When the Brackets/Parenthesis checking is validated then convert the expression to its equivalent post-fix expression. o Replace the given input linked list with the postfix linked list while maintaining the node the count value should be stored at the first node of the linked list