name = input(" Enter:")
def greet(name):
    print("Hello!" + name)
greet(" " + name)

#Types of fuctions
'''
1) Built in functions: already present in python
  examples: print(), sum(), len(), exit(), etc
2) User defined fuctions; defined by users by using "def"
  examples: greet(), percent(), etc ( which is added after 'def')
  '''
