“So, with trepidation, Cornfield and Leontief began subdividing the sectors until they ended with the simplest matrix they thought would be feasible, a 24 x 24 matrix. They both knew this was beyond the capacity of a single human being. Cornfield estimated that it would take him several hundred years of seven-day workweeks to invert a 24 x 24 matrix."

from The Lady Tasting Tea, by David Salsburg