diff --git a/ParadoxSaveParser.CLI/Modes/Interactive.cs b/ParadoxSaveParser.CLI/Modes/Interactive.cs
index fe094a8..24d8882 100644
--- a/ParadoxSaveParser.CLI/Modes/Interactive.cs
+++ b/ParadoxSaveParser.CLI/Modes/Interactive.cs
@@ -75,7 +75,7 @@ internal static partial class Modes
                         ColoredConsole.Write("Input file path: ", ConsoleColor.Blue);
                         input = ColoredConsole.ReadLine(ConsoleColor.Gray);
                         if (string.IsNullOrEmpty(input))
-                            throw new NullReferenceException();
+                            throw new ArgumentException("Input file path is required");
                         inputPath = input;
                         break;
 
@@ -83,9 +83,9 @@ internal static partial class Modes
                     case "output":
                         ColoredConsole.Write("Output file path [default=stdout]: ", ConsoleColor.Blue);
                         input = ColoredConsole.ReadLine(ConsoleColor.Gray);
-                        if (string.IsNullOrEmpty(input))
-                            throw new ArgumentException("Input file path is required");
-                        inputPath = input;
+                        if(string.IsNullOrEmpty(input))
+                            outputPath = null;
+                        else outputPath = input;
                         break;
 
                     case "s":
diff --git a/ParadoxSaveParser.Lib/SearchExpression.cs b/ParadoxSaveParser.Lib/SearchExpression.cs
index 1acd038..113248d 100644
--- a/ParadoxSaveParser.Lib/SearchExpression.cs
+++ b/ParadoxSaveParser.Lib/SearchExpression.cs
@@ -41,7 +41,8 @@ public static class SearchExpressionCompiler
             var subExprs = new List<ISearchExpression>();
             int supExprBegin = 1;
             int bracketBalance = 1;
-            for (int i = supExprBegin; i < query.Length && bracketBalance != 0; i++)
+            int i = supExprBegin;
+            for (; i < query.Length && bracketBalance != 0; i++)
             {
                 if (CharEqualsAndNotEscaped('(', query, i))
                 {
@@ -60,7 +61,7 @@ public static class SearchExpressionCompiler
                 }
             }
 
-            if (query[^1] != ')')
+            if (i != query.Length)
                 throw new NotImplementedException("Expressions after ')' are not supported");
 
             if (bracketBalance > 0)
@@ -68,7 +69,7 @@ public static class SearchExpressionCompiler
             if (bracketBalance < 0)
                 throw new Exception("Too many closing brackets");
 
-            var subPartLast = query.Slice(supExprBegin, query.Length - supExprBegin - 1);
+            var subPartLast = query.Slice(supExprBegin, i - 1 - supExprBegin);
             var subExprLast = Compile(subPartLast);
             subExprs.Add(subExprLast);
             return new MultipleMatchExpression(subExprs);