diff --git a/com/abdulfatir/jcomplexnumber/ComplexNumber.java b/com/abdulfatir/jcomplexnumber/ComplexNumber.java
index f761c1d..00e9218 100644
--- a/com/abdulfatir/jcomplexnumber/ComplexNumber.java
+++ b/com/abdulfatir/jcomplexnumber/ComplexNumber.java
@@ -347,6 +347,8 @@ else if(s.lastIndexOf('-') > 0)
 			{
 				s = s.replaceAll("i","");
 				s = s.replaceAll("I","");
+                if (s.equals("")) { s = "1"; }
+                else if (s.equals("-")) { s = "-1"; }
 				parsed = new ComplexNumber(0, Double.parseDouble(s));
 			}
 			// Pure real number