#! /usr/bin/env ruby

if ARGV.length != 1
        abort("Incorrect arguments - needs input file")
elsif not File.exist? (ARGV[0])
	abort("File #{ARGV[0]} did not exist")
end

file = ARGV[0]

platform = File.open(file, "r").each_line(chomp: true).map {|row| row.each_char.to_a}.to_a.transpose()

COL_SIZE = platform[0].length

chunked_platform = platform.map {|col| col.chunk_while {|i, j| i != "#"}.to_a}
total_load = chunked_platform.reduce(0) do |weight, col|
	_, col_weight = col.reduce([COL_SIZE, 0]) do |accum, chunk|
		first_obj_weight, temp_weight = accum
		num_moved_objs = chunk.count("O")
		last_obj_weight = first_obj_weight - num_moved_objs
		temp_weight += ((first_obj_weight * (first_obj_weight + 1)) / 2) - ((last_obj_weight * (last_obj_weight + 1)) / 2)
		first_obj_weight -= chunk.length
		[first_obj_weight, temp_weight]
	end
	weight + col_weight
end
puts total_load