Error:(26,13) no Android Studio 3.2.2

Professor exercício solicitado de Cesar:

package br.com.alura.cursoandroid;

import androidx.appcompat.app.AppCompatActivity;

import android.os.Bundle;

public class MainActivity extends AppCompatActivity {

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
}

}