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.