def main():
  print("main function")

def sum_(L):
  """ L is a list of integers
  returns the sum of all elements of the list"""

  # put your code here

def average(L):
  """ L is a list of integers
  returns the average of all elements of the list"""

  # put your code here

def sumOfSquares(L):
  """ L is a list of integers
   returns a new list of squares of elements of list L,
   does not modify the original list """

  # put your code here

def product(L):
  """ L is a list of integers
  returns the product of all elements of the list"""

  # put your code here

def min_(L):
  """ L is a list of integers
  returns the smallest element of the list"""

  # put your code here

def max_(L):
  """ L is a list of integers
  returns the greatest element of the list"""

  # put your code here

def readFromFile():
  """ prompts for the file name,
  reads values from it (separated by space and new line),
  stores them in a list,
  returns the list of values from file """

  # put your code here

def outputToFile(s):
  """ prompts for the file name,
  writes string s into it """

  # put your code here