Euler Project question in Python

# This Python file uses the following encoding:utf-8
# starting in the top left corner for a 2x2 grid, and only being able to move to the right and down, there is exactly 6 ro Utes to the bottom right corner.

# How many such routes is there through a 20x20 grid?
# pictures See at Https://projecteuler.net/problem=15
Import time
Start = Time.time ()
def factorial (n):
sum = 1
For I in range (2, n+1):
Sum *= I
return sum
Print "%s ways ways found in%s seconds"% (factorial (+)/(factorial (+) *factorial), Time.time ()-start)

Euler Project question in Python