diff --git a/wc.rb b/wc.rb
index 32d182c..37f1768 100644
--- a/wc.rb
+++ b/wc.rb
@@ -3,12 +3,12 @@
 require 'optparse'
 
 def main
-  options, sources = parse_options
-  file_stats = collect_file_stats(sources)
+  options, filenames = parse_options
+  file_stats = collect_file_stats(filenames)
   total_stats = calculate_total_stats(file_stats)
-  max_widths = calculate_max_widths(file_stats, total_stats)
+  max_widths = calculate_max_widths(file_stats + [total_stats])
   print_file_stats(file_stats, max_widths, options)
-  print_file_stats([{ filename: '合計', **total_stats }], max_widths, options) if sources.size > 1
+  print_file_stats([total_stats], max_widths, options) if filenames.size > 1
 end
 
 def parse_options
@@ -19,19 +19,19 @@ def parse_options
     opts.on('-c') { options[:bytes] = true }
   end.parse!
   options = { bytes: true, lines: true, words: true } if options.empty?
-  sources = ARGV.empty? ? [''] : ARGV
-  [options, sources]
+  filenames = ARGV.empty? ? [''] : ARGV
+  [options, filenames]
 end
 
-def collect_file_stats(sources)
-  sources.map do |source|
-    input = source.empty? ? ARGF.read : File.read(source)
-    { filename: source, lines: input.lines.count, words: input.split.size, bytes: input.bytesize }
+def collect_file_stats(filenames)
+  filenames.map do |filename|
+    input = filename.empty? ? ARGF.read : File.read(filename)
+    { filename: filename, lines: input.lines.count, words: input.split.size, bytes: input.bytesize }
   end
 end
 
 def calculate_total_stats(file_stats)
-  total_stats = { lines: 0, words: 0, bytes: 0 }
+  total_stats = { filename: '合計', lines: 0, words: 0, bytes: 0 }
   file_stats.each do |stats|
     total_stats[:lines] += stats[:lines]
     total_stats[:words] += stats[:words]
@@ -40,8 +40,7 @@ def calculate_total_stats(file_stats)
   total_stats
 end
 
-def calculate_max_widths(file_stats, total_stats)
-  all_stats = file_stats + [total_stats]
+def calculate_max_widths(all_stats)
   %i[lines words bytes].each_with_object({}) do |key, max_widths|
     max_widths[key] = all_stats.map { |stats| stats[key].to_s.length }.max
   end