p ARGF.readlines(chomp: true).map {|row|
  springs, groups = row.split(" ")
  [springs, groups.scan(/\d+/).map(&:to_i)]
}.map {|springs, groups|
  unknowns = springs.count(??)
  (0...2**unknowns).map {|arrangement|
    arrangement = arrangement.to_s(2).rjust(unknowns, ?0).chars.map { _1 == ?0 ? ?. : ?# }
    candidate = springs.gsub(??) { arrangement.shift }
    candidate.chars
      .slice_when { _1 != _2 }
      .reject { _1[0] == ?. }
      .map(&:size) == groups
  }.count(&:itself)
}.sum