diff --git a/awakia/kana.rb b/awakia/kana.rb
new file mode 100644
index 0000000..67e8ce3
--- /dev/null
+++ b/awakia/kana.rb
@@ -0,0 +1,32 @@
+# coding: utf-8
+
+def dic
+  {
+    'a' => '1',
+    'b' => '2',
+    'bc' => '3',
+    'cd' => '4',
+  }
+end
+
+def convert(input, output)
+  #p "#{input},#{output}"
+  if input.size == 0
+    return output
+  end
+  dic.each do |k, v|
+    if input.index(k) == 0
+      ret = convert(input[k.size..-1], output + v)
+      if ret != '$'
+        return ret
+      end
+    end
+  end
+  return '$'
+end
+
+p convert('a', '')
+p convert('b', '')
+p convert('ab', '')
+p convert('abc', '')
+p convert('abcd', '')