App crashing on startup in kitkat

[vaibhavsingh97]

java.lang.RuntimeException: Unable to start activity ComponentInfo{com.bml67.android.a67thmilestonebml/com.bml67.android.a67thmilestonebml.MainActivity}: java.lang.IllegalStateException: You need to use a Theme.AppCompat theme (or descendant) with this activity.
	at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2187)
	at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2236)
	at android.app.ActivityThread.access$800(ActivityThread.java:138)
	at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1199)
	at android.os.Handler.dispatchMessage(Handler.java:102)
	at android.os.Looper.loop(Looper.java:136)
	at android.app.ActivityThread.main(ActivityThread.java:5095)
	at java.lang.reflect.Method.invokeNative(Native Method)
	at java.lang.reflect.Method.invoke(Method.java:515)
	at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:786)
	at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:602)
	at dalvik.system.NativeStart.main(Native Method)
Caused by: java.lang.IllegalStateException: You need to use a Theme.AppCompat theme (or descendant) with this activity.
	at android.support.v7.app.AppCompatDelegateImplV9.createSubDecor(AppCompatDelegateImplV9.java:347)
	at android.support.v7.app.AppCompatDelegateImplV9.ensureSubDecor(AppCompatDelegateImplV9.java:316)
	at android.support.v7.app.AppCompatDelegateImplV9.setContentView(AppCompatDelegateImplV9.java:281)
	at android.support.v7.app.AppCompatActivity.setContentView(AppCompatActivity.java:140)
	at com.bml67.android.a67thmilestonebml.MainActivity.onCreate(MainActivity.java:28)
	at android.app.Activity.performCreate(Activity.java:5231)
	at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1087)
	at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2151)