At the posted coordinates you will find a sign with a large 2 digit number on it.
A = the first digit of the number
B = the second digit of the number
North : 43 ((13 x A) + 2 - B).((50 x A) + B - 1)
West : 079 ((3 x A) + 2 - B).((73 x A) + B - 2)
The last digit in the north coordinates is 9 and the last digit in the west coordinates is 0.