first_hash = Hash.new
second_hash = Hash.new

first = File.open('first.txt', 'r')
second = File.open('second.txt', 'r')

first.each do |line|
    line = line.split(/\t/)
    supID = line[0]
    contID = line[1]
    cbsa = line[2]
    ctgy = line[3]
    first_hash["#{contID}|""#{cbsa}|""#{ctgy}"] ||= []
    first_hash["#{contID}|""#{cbsa}|""#{ctgy}"] << "#{supID}"
end

first_hash.each do |key, value|
    key = key.split("|")
    contID = key[0]
    cbsa = key[1]
    ctgy = key[2]
    second.each do |line|
        line = line.split(/\t/)
        contID = line[0]
        cbsa = line[1]
        ctgy = line[2]
        mftr = line[3]
        model = line[4].strip
        value.each do |item|
            second_hash["#{contID}|""#{cbsa}|""#{ctgy}|""#{item}"] ||= []
            second_hash["#{contID}|""#{cbsa}|""#{ctgy}|""#{item}"] << "#{model}"
        end
    end
end

puts second_hash