diff --git a/src/main/java/haidnor/jvm/Main.java b/src/main/java/haidnor/jvm/Main.java
index 14cb7d5..564250c 100644
--- a/src/main/java/haidnor/jvm/Main.java
+++ b/src/main/java/haidnor/jvm/Main.java
@@ -1,5 +1,12 @@
 package haidnor.jvm;
 
+import org.apache.commons.cli.CommandLine;
+import org.apache.commons.cli.CommandLineParser;
+import org.apache.commons.cli.DefaultParser;
+import org.apache.commons.cli.Option;
+import org.apache.commons.cli.OptionGroup;
+import org.apache.commons.cli.Options;
+
 import haidnor.jvm.classloader.ClassLoader;
 import haidnor.jvm.core.JavaExecutionEngine;
 import haidnor.jvm.rtda.heap.Klass;
@@ -9,7 +16,6 @@ import haidnor.jvm.runtime.JvmThread;
 import haidnor.jvm.util.JavaClassUtil;
 import haidnor.jvm.util.JvmThreadHolder;
 import lombok.SneakyThrows;
-import org.apache.commons.cli.*;
 
 /**
  * @author wang xiang
@@ -41,7 +47,7 @@ public class Main {
             Klass mainMeteKlass = bootClassLoader.loadClassWithAbsolutePath(path);
             KlassMethod mainKlassMethod = JavaClassUtil.getMainMethod(mainMeteKlass);
             Metaspace.registerJavaClass(mainMeteKlass);
-
+            
             JavaExecutionEngine.callMainStaticMethod(mainKlassMethod);
         }
     }
diff --git a/src/main/java/haidnor/jvm/instruction/stores/FSTORE.java b/src/main/java/haidnor/jvm/instruction/stores/FSTORE.java
index 354aabd..0b21d8b 100644
--- a/src/main/java/haidnor/jvm/instruction/stores/FSTORE.java
+++ b/src/main/java/haidnor/jvm/instruction/stores/FSTORE.java
@@ -11,7 +11,7 @@ public class FSTORE extends Instruction {
 
     public FSTORE(CodeStream codeStream) {
         super(codeStream);
-        this.index = codeStream.readUnsignedShort(this);
+        this.index = codeStream.readUnsignedByte(this);
     }
 
     @Override
diff --git a/src/main/java/haidnor/jvm/instruction/stores/ISTORE.java b/src/main/java/haidnor/jvm/instruction/stores/ISTORE.java
index 20095e2..596adcc 100644
--- a/src/main/java/haidnor/jvm/instruction/stores/ISTORE.java
+++ b/src/main/java/haidnor/jvm/instruction/stores/ISTORE.java
@@ -11,7 +11,7 @@ public class ISTORE extends Instruction {
 
     public ISTORE(CodeStream codeStream) {
         super(codeStream);
-        this.index = codeStream.readUnsignedShort(this);
+        this.index = codeStream.readUnsignedByte(this);
     }
 
     @Override