Help How to fix this error message

[Mohamed13]

Android manifest code
<?xml version="1.0" encoding="utf-8"?>
<manifest
xmlns:android="http://schemas.android.com/apk/res/android"
android:versionCode="1"
android:versionName="1.0"
package="com.example.Second app">

<uses-sdk android:minSdkVersion="15" android:targetSdkVersion="26" />

<application
android:allowBackup="true"
android:icon="@Mipmap/ic_launcher"
android:roundIcon="@Mipmap/ic_launcher_round"
android:label="second app"
android:supportsRtl="true"
android:theme="@Style/AppBaseTheme">
<activity android:name="com.example.secondapp.FullscreenActivity">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
</manifest>
The error message is Cannot resolve symbol '@Style/AppBaseTheme'
This is build output error message.