#!/bin/env ruby

ids = File.readlines('./input').map(&:strip)
checksum = {twos: 0, threes: 0}

ids.map! { |id| id.each_char.tally.delete_if { |char, count| count==1 }}
ids.each do |id|
    checksum[:twos] += 1 if id.has_value?(2)
    checksum[:threes] += 1 if id.has_value?(3)
end

puts checksum[:twos] * checksum[:threes]