diff --git a/lojysamban.cabal b/lojysamban.cabal
--- a/lojysamban.cabal
+++ b/lojysamban.cabal
@@ -2,7 +2,7 @@
 cabal-version:		>= 1.6
 
 name:			lojysamban
-version:		0.0.4
+version:		0.0.5
 stability:		experimental
 author:			.iocikun.juj. <PAF01143@nifty.ne.jp>
 maintainer:		.iocikun.juj. <PAF01143@nifty.ne.jp>
diff --git a/lojysamban2.hs b/lojysamban2.hs
--- a/lojysamban2.hs
+++ b/lojysamban2.hs
@@ -19,7 +19,13 @@
 
 main :: IO ()
 main = do
-	[fn] <- getArgs
+	args <- getArgs
+	fn <- case args of
+		[] -> do
+			putStr "Please enter source file name: "
+			hFlush stdout
+			getLine
+		[fn] -> return fn
 	src <- readFile fn
 	let	Right p = parse src
 		rules = map readSentence $ getSentences p
