diff --git a/ChangeLog.md b/ChangeLog.md
--- a/ChangeLog.md
+++ b/ChangeLog.md
@@ -48,3 +48,8 @@
 ## 0.5.2.0 -- 2020-09-19
 
 * Fifth version revised B. Fixed issue with parse error for the uniqVec03 executable in the CPP preprocessor. 
+
+## 0.5.3.0 -- 2020-09-20
+
+* Fifth version revised C. Fixed issue with parsing empty second command line argument (or its absense, actually). 
+
diff --git a/Proportion/Main.hs b/Proportion/Main.hs
--- a/Proportion/Main.hs
+++ b/Proportion/Main.hs
@@ -27,7 +27,8 @@
 import GHC.Base (mconcat)
 #endif
 #endif
-import Control.Exception (onException)
+import Data.Maybe (isNothing,fromJust)
+import Text.Read (readMaybe)
 import qualified Data.Vector as V
 import String.Languages.UniquenessPeriods.Vector
 import Languages.UniquenessPeriods.Vector.General.Debug
@@ -55,7 +56,8 @@
 main = do
   args <- getArgs
   let file = concat . take 1 $ args
-  gz <- onException (do {return (read (concat . take 1 . drop 1 $ args)::Int)}) (return 9)
+      gzm = readMaybe (concat . take 1 . drop 1 $ args)::(Maybe Int)
+      gz = if isNothing gzm then 9 else fromJust gzm
   contents <- readFile file
   let flines = filter (not . null . filter isUkrainian) . prepareText $ contents
   data3 <- mapM (\ts -> do
diff --git a/uniqueness-periods-vector-examples.cabal b/uniqueness-periods-vector-examples.cabal
--- a/uniqueness-periods-vector-examples.cabal
+++ b/uniqueness-periods-vector-examples.cabal
@@ -3,7 +3,7 @@
 -- http://haskell.org/cabal/users-guide/
 
 name:                uniqueness-periods-vector-examples
-version:             0.5.2.0
+version:             0.5.3.0
 synopsis:            Examples of usage for the uniqueness-periods-vector series of packages
 description:         Examples of usage for the uniqueness-periods-vector series of packages. Several executables are planned to demonstrate the libraries work.
 homepage:            https://hackage.haskell.org/package/uniqueness-periods-vector-examples