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(import (chicken string))
(import (chicken io))
(import (chicken sort))
(import matchable)
(import srfi-1)
(import regex)
(define input
(with-input-from-file "input"
(lambda ()
(let loop ((ret '()))
(let ((line (read-line)))
(if (eof-object? line)
(reverse ret)
(loop (cons line ret))))))))
(define (transpose in)
(define cols (string-length (car in)))
(let loop ((i 0) (ret '()))
(if (>= i cols)
(reverse ret)
(loop (+ i 1) (cons (list->string (map (lambda (x) (string-ref x i))
in))
ret)))))
(define (flip in)
(define (flip-row row)
(list->string (reverse (string->list row))))
(map flip-row in))
(define (char-at in x y)
(string-ref (list-ref in y) x))
(define (diag in)
(define width (string-length (car in)))
(define height (length in))
(define (diag-start-at x y)
(let loop ((cur-row y) (cur-col x) (ret '()))
(if (or (< cur-col 0)
(>= cur-row height))
(list->string (reverse ret))
(loop (+ cur-row 1)
(- cur-col 1)
(cons (char-at in cur-col cur-row) ret)))))
(define (row-diag in)
(let loop ((i 0) (ret '()))
(if (>= i width)
(reverse ret)
(loop (+ 1 i) (cons (diag-start-at i 0) ret)))))
(define (col-diag in)
(let loop ((i 1) (ret '()))
(if (>= i height)
(reverse ret)
(loop (+ i 1) (cons (diag-start-at (- width 1) i) ret)))))
(append (row-diag in) (col-diag in)))
(define (count-xmas str)
(define len (string-length str))
(let loop ((cur 0) (count 0))
(define pos (string-search-positions "XMAS" str cur))
(if pos
(loop (cadar pos) (+ 1 count))
count)))
(define (count-mat mat)
(apply + (map count-xmas mat)))
(define mat-list
(list input (flip input)
(transpose input) (flip (transpose input))
(diag input) (flip (diag input))
(diag (flip input)) (flip (diag (flip input)))))
(display (apply + (map count-mat mat-list)))
(newline)
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