title: R.java was modified manually. Reverting to generated version
body: <p>An error how to fix it?
  R.java was modified manually! Reverting to generated version!
  to drain setContentView(R.layout.main);</p>
  
  <pre><code>enter code here
  
  package com.sposib.urav;
  
  import android.app.Activity;
  import android.os.Bundle;
  import android.view.View;
  import android.view.View.OnClickListener;
  import android.widget.Button;
  import android.widget.EditText;
  import android.widget.Toast;
  
  public class UravActivity extends Activity implements OnClickListener {
  /** Called when the activity is first created. */
  private EditText A;
  private EditText B;
  private EditText C;
  private Button Clean;
  private Button Solve;
  private static final double ACCURACY=1000;
  @Override
  public void onCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
      setContentView(R.layout.main);
      A=(EditText) findViewById(R.id.a);
      B=(EditText) findViewById(R.id.b);
      C=(EditText) findViewById(R.id.c);
      Clean=(Button) findViewById(R.id.cl);
      Solve=(Button) findViewById(R.id.sl);
      Clean.setOnClickListener(this);
      Solve.setOnClickListener(this);
  </code></pre>
  
  <p>Thanks for reading</p>