COLORS = %w[ red green blue ]

puts DATA.readlines.sum { |line|
  _game, rounds = line.match(/Game (\d+): (.+)/).captures
  rounds = rounds.split("; ").map { _1.scan(/(\d+) (\w+)/) }

  COLORS.map { |color| rounds.filter_map { |round| round.find { _2 == color }&.first&.to_i }.max }.reduce(:*)
  # Alt:
  #COLORS.map { |color| rounds.flat_map { |round| round.filter_map { _1.to_i if _2 == color } }.max }.reduce(:*)
}

__END__
Data goes here