gistfile1.rb

#coding: utf-8
require 'socket'
def solve(cnt, the_end)
    pattern = {111 => [471], 333 => [477], 777 => [753], 888 => [192, 442, 692, 942], 999 => [999]}
    
    a = (cnt-1) / pattern[the_end].length
    b = pattern[the_end][cnt % pattern[the_end].length - 1]
    return a.to_s + b.to_s
end
# puts solve(265613988875874769338781322035779626829233452653394495974574961739092490901302182994384699044001, 888)

def get_problem(s)
    line = ""
    while true
        c = s.read(1)
        return line if c == nil
        
        line += c
        if c == "?"
            return line
        end
    end
end

#main
s = TCPSocket.open("nullcon-e1.no-ip.org", 2000)
p s.gets; p s.gets; p s.gets;
loop do
    p line = get_problem(s)
    if line =~ /What is the (\d+)(?:th|rd|st|nd) positive integer whose cube ends with the digits (\d+)?/
        cnt = $1
        the_end = $2
        puts ans = solve(cnt.to_i, the_end.to_i).to_s
        s.puts ans
    else
        p line
        break
    end
end