from cs1graphics import *

w = 580
h = 320
paper = Canvas(w,h)
paper.setBackgroundColor('gray')

for x in range(0,w,100):
    line = Path( Point(x,0), Point(x,h) )
    paper.add(line)

for y in range(0,h,100):
    line = Path( Point(0,y), Point(w,y) )
    paper.add(line)