import java.io.*;

public class Keyboard {

  public static String readString()
  {
    BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
    String s = "";
    try{s = br.readLine();}
    catch(IOException e) {System.out.print("Valor Inválido.");}
    return s;
  }

  public static int readInteger()
  {
    BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
    String s = "";
    try{s = br.readLine();}
    catch(IOException e) {System.out.print("Valor Inválido.");}
    return Integer.parseInt(s);
  }

  public static double readDouble()
  {
    BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
    String s = "";
    try{s = br.readLine();}
    catch(IOException e) {System.out.print("Valor Inválido.");}
    Double d = new Double(s);
    return d.doubleValue();
  }
}