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.

C$++$

private:

struct Node $\{$

int value;

Node $*$next;

$\}$;