Factorial of any number is multiplication of all 1,2,3,4,.... upto that number.
Function call itself is called recursion.
stack is use to implement the recursion
print("Factorial is - "+str(ans))
Factorial is - 720
In this program, we use recursion to find the factorial of the number, func() is a function which call again and again with the decrease value of n and when the value of n will become 1 so we return 1 to function and we backtrack the all function calling and store the result in ans