What is funcation.?
>> Functions are reusable pieces of programs.

>> The function concept is probably the most important building block of any non-trivial software.

>> Functions are defined using the def keyword. After this keyword comes an identifier name for the function, followed by a pair of parentheses which may enclose some names of variables, and by the final colon that ends the line.


# define of main function.
def main():
	print("hello world")

# call the main function.
	main()
print("amit")
