# David Powis-Dow CS 101:Python 
# 2016-12-03 v0.1
# Chapter 4 : Exercise - Sum_to fruitful function    

def sum_to(n):
    """
      Returns the sum of  of all integer numbers up and including n.
    """
    for i in range(10):    
        a = a + x + 1
    return a 

sum_to(10)

print(sum_to(10))





