(def tbl [[0 3 1 7 5 9 8 6 4 2] [7 0 9 2 1 5 4 8 6 3] [4 2 0 6 8 7 1 3 5 9] [1 7 5 0 9 8 3 4 2 6] [6 1 2 3 0 4 5 9 7 8] [3 6 7 4 2 0 9 5 8 1] [5 8 6 9 7 2 0 1 3 4] [8 9 4 5 3 6 2 0 1 7] [9 4 3 8 6 1 7 2 0 5] [2 5 8 1 4 3 6 7 9 0]]) (defn damm? [digits] (= 0 (reduce #(nth (nth tbl %1) %2) 0 (map #(Character/getNumericValue %) (seq digits)))))