import java.util.*;
import java.util.zip.*;
import java.util.List;
import java.util.regex.*;
import java.util.concurrent.*;
import java.util.concurrent.atomic.*;
import java.util.concurrent.locks.*;
import java.util.function.*;
import javax.swing.*;
import javax.swing.event.*;
import javax.swing.text.*;
import javax.swing.table.*;
import java.io.*;
import java.net.*;
import java.lang.reflect.*;
import java.lang.ref.*;
import java.lang.management.*;
import java.security.*;
import java.security.spec.*;
import java.awt.*;
import java.awt.event.*;
import java.awt.image.*;
import java.awt.geom.*;
import javax.imageio.*;
import java.math.*;
import java.time.Duration;
import java.lang.invoke.VarHandle;
import java.lang.invoke.MethodHandles;
class main {

static class DoubleVar {
  double a; // you can access this directly if you use one thread
  
  DoubleVar() {}
  DoubleVar(double a) {
  this.a = a;}
  
  public synchronized void set(double v) {
    if (v != a) {
      a = v;
      notifyAll();
    }
  }
  
  public synchronized double get() { return a; }

  synchronized double waitForValue(double x) { try {
    while (a != x) wait();
    return a;
  } catch (Exception __e) { throw rethrow(__e); } }
  
  public String toString() { return str(this.get()); }
}
static RuntimeException rethrow(Throwable t) {
  
  if (t instanceof Error)
    _handleError((Error) t);
  
  throw t instanceof RuntimeException ? (RuntimeException) t : new RuntimeException(t);
}

static RuntimeException rethrow(String msg, Throwable t) {
  throw new RuntimeException(msg, t);
}


static String str(Object o) {
  return o == null ? "null" : o.toString();
}

static String str(char[] c) {
  return new String(c);
}

static String str(char[] c, int offset, int count) {
  return new String(c, offset, count);
}




static void _handleError(Error e) {
  //call(javax(), '_handleError, e);
}



}