diff --git a/.gitignore b/.gitignore
index b9d6bd9..2910209 100644
--- a/.gitignore
+++ b/.gitignore
@@ -213,3 +213,10 @@ pip-log.txt
 
 #Mr Developer
 .mr.developer.cfg
+
+
+#################
+## IntelliJ
+#################
+.idea/
+*.iml
\ No newline at end of file
diff --git a/Fibonacci.java b/Fibonacci.java
index bd43c74..a6360f4 100644
--- a/Fibonacci.java
+++ b/Fibonacci.java
@@ -1,6 +1,12 @@
 public class Fibonacci{
 
      public static void main(String []args){
+         if(args.length  == 0)
+         {
+             System.out.println("입력된 수가 없습니다.\n프로그램을 종료합니다.");
+             return;
+         }
+
          int start = Integer.parseInt(args[0]);
          int fib1 = 0;
          int fib2 = 1;