StatefulWidget wont change

main.dart

import 'package:flutter/material.dart';

void main() => runApp(MyApp());

class MyApp extends StatefulWidget {
  @override
  State<StatefulWidget> createState() {
    return _MyAppState();
  }
}

class _MyAppState extends State<MyApp> {
  int value = 0;
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        appBar: AppBar(title: Text('App Example')),
        body: Row(children:[
          MyStatefulWidget(title: value.toString()), 
          RaisedButton(
            textColor: Colors.white,
            color: Colors.blue,
            onPressed: (){setState(() { value+=1; });},
            child: new Text("Add"),
          )
        ]),
      ),
    );
  }
}

class MyStatefulWidget extends StatefulWidget {
  MyStatefulWidget({Key key, this.title}):super(key: key);
  final String title;
  
  @override
  State<StatefulWidget> createState() {
    return _MyStatefulWidgetState();
  }
}

class _MyStatefulWidgetState extends State<MyStatefulWidget> {
  String title;
   @override
  void initState() {
    super.initState();
    if (widget.title!=null) {
      title = widget.title;
    } else {
      title = "";
    }
  }
  int value = 0;
  @override
  Widget build(BuildContext context) {
    return Text(title);
  }
}