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 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 javax.imageio.*;
import java.math.*;
class main {

static <A> A $x(Map<String, A> map) {
  return mapGet(map, "$x");
}
static <A, B> B mapGet(Map<A, B> map, A a) {
  return map == null || a == null ? null : map.get(a);
}

static <A, B> B mapGet(A a, Map<A, B> map) {
  return map == null || a == null ? null : map.get(a);
}

}