# c03ex11.py
#    Sum of first n natural numbers

def main():
    print "This program finds the sum of the first n natural numbers."
    print

    n = input("Please enter a value for n: ")
    sum = 0
    for i in range(1,n+1):
        sum = sum + i

    print
    print "The sum from 1 to", n, "is:", sum

main()