import turtle
turtle.speed(0)
turtle.pensize(5)
turtle.color("black")
turtle.forward(100)
turtle.right(90)
turtle.forward(50)
turtle.right(90)
turtle.forward(50)
turtle.right(90)
turtle.forward(50)
turtle.right(90)
turtle.forward(50)
turtle.right(90)
turtle.forward(100)
turtle.penup()
turtle.goto(-50, 100)
turtle.pendown()
turtle.circle(25)
turtle.penup()
turtle.goto(50, 100)
turtle.pendown()
turtle.circle(25)
turtle.penup()
turtle.goto(-50, 50)
turtle.pendown()
turtle.right(90)
turtle.forward(100)
turtle.left(90)
turtle.forward(100)
turtle.right(90)
turtle.forward(100)
turtle.left(90)
turtle.forward(100)
turtle.penup()
turtle.goto(-50, -50)
turtle.pendown()
turtle.right(90)
turtle.forward(50)
turtle.right(90)
turtle.forward(50)
turtle.right(90)
turtle.forward(50)
turtle.right(90)
turtle.forward(50)
turtle.right(90)
turtle.forward(50)
turtle.right(90)
turtle.forward(50)
turtle.right(90)
turtle.forward(50)
turtle.right(90)
turtle.forward(50)
turtle.right(90)
turtle.forward(50)
turtle.right(90)
turtle.forward(50)