In C++, declare and implement a class to represent a stack of integers, called IntStack. Include the following functions in your class:

a default constructor that creates an empty stack.

a void function for push(x) that inserts a new value onto the top of the stack.

an int function for pop() that removes the value from the top of the stack, and returns it (if the stack is empty, it returns -1).

a boolean function isempty() that returns true if the stack is empty, otherwise false.

Implement the class functions using a linked list composed of Nodes to store the values in the stack. Hint: push(x) should add x to the front of the list and pop should remove the element at the front of the list. Use the following declarations in your class:

// C++ private: struct Node { int value; Node *next; }