"Crude Scrawling at X:10.5, Y:13.8: A wise artithmetican once said the primes were the most lonesome of numbers. To that I say bollocks! 2, 3, 5, 7, 11, 13, 17, 19, 23, 31 ... and so on to eternity. There are enough digits here to start a fellowship!"


It literally tells you in the dungeon which numbers count.