diff --git a/check_similar b/check_similar
new file mode 100755
--- /dev/null
+++ b/check_similar
@@ -0,0 +1,93 @@
+#!/usr/bin/env ruby
+
+def config
+  Grader::Configuration.get_instance
+end
+
+def display_manual
+  puts <<USAGE
+Check similarity between submission
+using: check_similar sub1 sub2
+          -- or --
+       check_similar problem_name
+  sub1 and sub2   are submission IDs to be checked
+  problem_name    will check all submissions of the problem wit problem short name is 'problem_name'
+
+  The output are given as
+    sub1.login, sub1.id, sub1.point, sub2.login, sub2.id, sub2.point, similarity
+
+USAGE
+end
+
+def process_options_and_stop_file
+
+  # Process 'help' option
+  if (ARGV.length == 0) or ((ARGV.length==1) and (/help/.match(ARGV[0])))
+    display_manual
+    exit(0)
+  end
+
+  #default options
+  options = {
+    :dry_run => false,
+  }
+
+
+  if ARGV.length == 2
+    options[:sub1] = ARGV[0].to_i
+    options[:sub2] = ARGV[1].to_i
+  elsif ARGV.length == 1
+    options[:problem] = ARGV[0]
+  end
+
+
+  return options
+end
+
+def compare(sub1,sub2,full = sub1.problem.full_score)
+  dis = @jarow.getDistance(sub1.source, sub2.source)
+  puts [sub1.user.login,"##{sub1.id}",(sub1.points * 100.0 / full).to_i,
+        sub2.user.login,"##{sub2.id}",(sub2.points * 100.0 / full).to_i,
+        "#{dis * 100}%"].join(',')
+end
+
+#########################################
+# main program
+#########################################
+
+options = process_options_and_stop_file
+
+# load grader environment
+GRADER_ENV = 'grading'
+require File.join(File.dirname(__FILE__),'config/environment')
+
+# boot rails, to be able to use the active record
+RAILS_ENV = config.rails_env
+require RAILS_ROOT + '/config/environment'
+
+# load comparator
+require 'fuzzystringmatch'
+@jarow = FuzzyStringMatch::JaroWinkler.create( :native )
+
+if options[:problem]
+  p = Problem.where(name: options[:problem]).first
+  unless p
+    puts "cannot find problem #{options[:problem]}"
+    exit(0)
+  end
+  subs = Submission.where(problem: p)
+  full_score = p.full_score.to_i
+  subs.each.with_index do |s1,i|
+    puts "processing #{i+1} out of #{subs.length}"
+    subs.each do |s2|
+      if s1.user != s2.user
+        compare(s1,s2,full_score)
+      end
+    end
+  end
+else
+  sub1 = Submission.find(options[:sub1])
+  sub2 = Submission.find(options[:sub2])
+  compare(sub1,sub2)
+end
+
diff --git a/grader-process-check b/grader-process-check
new file mode 100755
--- /dev/null
+++ b/grader-process-check
@@ -0,0 +1,6 @@
+#!/bin/bash
+count=`ps aux | grep "cafe_grader" | grep "grader grading queue" | wc -l`
+if [ $count -lt 1 ]; then
+  cd /home/dae/cafe_grader/judge
+  /home/dae/.rvm/wrappers/ruby-2.3.0/ruby /home/dae/cafe_grader/judge/scripts/grader grading queue > /home/dae/grading.log &
+fi
diff --git a/import_problem b/import_problem
--- a/import_problem
+++ b/import_problem
@@ -145,6 +145,12 @@
     end
   end
 
+  #also include any .txt files
+  Dir.glob("#{testcase_dir}/*.txt") do |file|
+    puts "copy data file #{file}"
+    FileUtils.cp(file,"#{problem_dir}")
+  end
+
   # generating all_tests.cfg
   puts "generating testcase config file"
 
diff --git a/load_testcase b/load_testcase
--- a/load_testcase
+++ b/load_testcase
@@ -20,7 +20,7 @@
 def process_options_and_stop_file
 
   # Process 'help' option
-  if (ARGV.length==1) and (/help/.match(ARGV[0]))
+  if (ARGV.length == 0) or ((ARGV.length==1) and (/help/.match(ARGV[0])))
     display_manual
     exit(0)
   end
@@ -74,7 +74,7 @@
 require RAILS_ROOT + '/config/environment'
 
 if options[:all]
-  Problem.all.each { |prob| process_problem(prob,options[:all]) }
+  Problem.all.each { |prob| process_problem(prob,options[:dry_run]) }
 else
   ARGV.each do |name|
     prob = Problem.find_by(name: name)
diff --git a/rename_problem b/rename_problem
--- a/rename_problem
+++ b/rename_problem
@@ -8,7 +8,7 @@
 
 def rename_problem(old_problem_name, new_problem_name)
 
-  if valid_problem_name(new_problem_name)
+  unless valid_problem_name(new_problem_name)
     puts "Bad new problem name: #{new_problem_name}"
     return
   end
@@ -60,7 +60,7 @@
   if name.length==0:
       return false
   else
-    return !(/^[a-zA-Z0-9_\-]+$/ === name)
+    return (/^[a-zA-Z0-9_\-]+$/ === name)
   end
 end
 
diff --git a/std-script/judge b/std-script/judge
--- a/std-script/judge
+++ b/std-script/judge
@@ -140,6 +140,12 @@
     if language == "python" then Dir["#{test_result_dir}/*.pyc"].each { |file| FileUtils.cp(file,sandbox_dir)} end
   }
 
+  #additionally copy any extra .txt file
+  data_files = Dir[problem_home + '/*.txt']
+  data_files.each do |file|
+    FileUtils.cp(file,sandbox_dir)
+  end
+
   begin
     execute("#{problem_home}/script/run #{language} #{test_num} ", "Error occured during execution of the run script")
   rescue
diff --git a/templates/check.float b/templates/check.float
--- a/templates/check.float
+++ b/templates/check.float
@@ -47,6 +47,11 @@
 
 ########### THIS IS FOR CHECKING FLOAT with EPSILON error ##########
 
+
+def is_float?(fl)
+  !!Float(fl) rescue false
+end
+
 EPSILON = 0.000001
 
 out_items = output_file_content.split
@@ -56,10 +61,14 @@
   report_wrong.call
 else
   out_items.length.times do |i|
-    out_value = out_items[i].to_f
-    ans_value = ans_items[i].to_f
-    if (out_value - ans_value).abs > EPSILON * [out_value.abs,ans_value.abs].max
-      report_wrong.call
+    if is_float?(out_items[i]) && is_float?(ans_items[i])
+      out_value = out_items[i].to_f
+      ans_value = ans_items[i].to_f
+      if (out_value - ans_value).abs > EPSILON * [out_value.abs,ans_value.abs].max
+        report_wrong.call
+      end
+    else
+      report_wrong.call if out_items[i] != ans_items[i]
     end
   end
   report_correct.call