n = 10
result = 0
for i in range(n + 1):
    result = result + i
print(result)

###

s = ""
for num in range(10, 14):
    subs = str(num) + "-"
    s = s + subs
print(s)

###

def isPrime(num):
    if num < 2:
        return False
    for factor in range(2, num):
        if num % factor == 0:
            return False
    return True

###

for x in range(1, 4):
  for y in range(1, 3):
    print(x, "*", y, "=", x * y)

###
    
import tkinter
def drawGrid(canvas, size):
    for row in range(size):
        top = row * 50
        bottom = top + 50
        for col in range(size):
            left = col * 50
            right = left + 50 # (col + 1)*50
            if row % 2 == 0:
                color = "red"
            else:
                color = "green"
            canvas.create_rectangle(left, top, right, bottom, fill=color)

def runDrawGrid():
    root = tkinter.Tk()
    canvas = tkinter.Canvas(root, width=400, 
                            height=400)
    canvas.configure(bd=0, 
                     highlightthickness=0)
    canvas.pack()

    drawGrid(canvas, 4) # your call here!

    root.mainloop()

runDrawGrid()