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diff --git a/AoC2023/day15/solver.lisp b/AoC2023/day15/solver.lisp
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+++ b/AoC2023/day15/solver.lisp
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+;; 17:04
+;; 17:34 part1
+(ql:quickload '(fiveam str))
+
+(defparameter eg-in "rn=1,cm-,qp=3,cm=2,qp-,pc=4,ot=9,ab=5,pc-,pc=6,ot=7")
+
+(defun hash (str)
+  (reduce
+   (lambda (acc c)
+     (mod (* 17 (+ acc (char-code c))) 256))
+   str :initial-value 0))
+
+(defun solve1 (in)
+  (reduce #'+
+          (str:split "," (str:trim in))
+          :key #'hash))
+
+(fiveam:test solutions
+  (fiveam:is (= 52 (hash "HASH")))
+  (fiveam:is (= 1320 (solve1 eg-in)))
+  (fiveam:is (= 506437 (solve1 (uiop:read-file-string "input")))))
+
+(fiveam:run!)