Solution to Problem 11. Written in Python.

Problem: In the 20 x 20 grid below, four numbers along a diagonal line have been marked in red. The product of these numbers is 26 x 63 x 78 x 14 = 1788696. What is the greatest product of four adjacent numbers in any direction (up, down, left, right, or diagonally) in the 20 x 20 grid? You can find the 20 x 20 grid on Project Euler.