diff --git a/README.md b/README.md
index d0de5ba..a352c5e 100644
--- a/README.md
+++ b/README.md
@@ -22,6 +22,8 @@ This screenshot is from `LeNet` branch, which uses camera.
 
 
 
+
+
 ## Preparation
 
-Please make sure the Android System on your phone is 8.1+, or you may want to use API 27 emulator. The beta version of NDK is necessary for NNAPI. If you want to compile the demo please use Android Studio 3.0+.
+Please make sure the Android System on your phone is 8.1+, or you may want to use API 27 emulator. The [beta version of NDK](https://developer.android.com/ndk/downloads/index.html#beta-downloads) is necessary for NNAPI. If you want to compile the demo please use Android Studio 3.0+.
diff --git a/build.gradle b/build.gradle
index 020eae2..0275b67 100644
--- a/build.gradle
+++ b/build.gradle
@@ -8,7 +8,8 @@ buildscript {
     }
     dependencies {
         classpath 'com.android.tools.build:gradle:3.0.0'
-        
+        classpath 'com.github.dcendents:android-maven-gradle-plugin:1.5'
+
 
         // NOTE: Do not place your application dependencies here; they belong
         // in the individual module build.gradle files
diff --git a/dnnlibrary/build.gradle b/dnnlibrary/build.gradle
index 3743833..1bf64d6 100644
--- a/dnnlibrary/build.gradle
+++ b/dnnlibrary/build.gradle
@@ -1,4 +1,8 @@
 apply plugin: 'com.android.library'
+apply plugin: 'com.github.dcendents.android-maven'
+
+group='com.github.daquexian'
+
 
 android {
     compileSdkVersion 27