patterns = ARGF.read.split("\n\n")
  .map { _1.split("\n").map(&:chars) }

def find_fold(pattern)
  (0.5...pattern.length-0.5).step(1).find {|fold|
    a = pattern[0..fold.floor]
    b = pattern[fold.ceil..]
    a.reverse.zip(b).reject { _1.any?(&:nil?) }.all? { _1 == _2 }
  }&.ceil
end

verts = patterns.map { find_fold(_1.transpose) }.compact
hors = patterns.map { find_fold(_1) }.compact
p verts.sum + hors.sum { _1 * 100 }