How to speed up python's 'turtle' function and stop it freezing at the end

Question

I have written a turtle program in python, but there are two problems.

1. It goes way too slow for larger numbers, I was wonder how I can speed up turtle.
2. It freezes after it finishes and when clicked on, says 'not responding'

This is my code so far:

import turtle

#Takes user input to decide how many squares are needed
f=int(input("How many squares do you want?"))
c=int(input("What colour would you like? red = 1, blue = 2 and green =3"))
n=int(input("What background colour would you like? red = 1, blue = 2 and green =3"))

i=1

x=65

#Draws the desired number of squares.
while i < f:
    i=i+1
    x=x*1.05
    print ("minimise this window ASAP")
    if c==1:
        turtle.pencolor("red")
    elif c==2:
        turtle.pencolor("blue")
    elif c==3:
        turtle.pencolor("green")
    else:
        turtle.pencolor("black")
    if n==1:
        turtle.fillcolor("red")
    elif n==2:
        turtle.fillcolor("blue")
    elif n==3:
        turtle.fillcolor("green")
    else:
        turtle.fillcolor("white")
    turtle.bk(x)
    turtle.rt(90)
    turtle.bk(x)
    turtle.rt(90)
    turtle.bk(x)
    turtle.rt(90)
    turtle.bk(x)
    turtle.rt(90)
    turtle.up()
    turtle.rt(9)
    turtle.down()

By the way: I am on version 3.2!

Answer 1

1. Set turtle.speed() to fastest.
2. Use the turtle.mainloop() functionality to do work without screen refreshes.
3. Disable screen refreshing with turtle.tracer(0, 0) then at the end do turtle.update()