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 {



// may return null when result is empty
static int[] intersectSortedIntArrays(int[] a, int[] b) { return intersectSortedIntArrays(a, b, null); }
static int[] intersectSortedIntArrays(int[] a, int[] b, IntBuffer buf) {
  int i = 0, j = 0, la = lIntArray(a), lb = lIntArray(b);
  
  // swap if a is longer than b
  if (la > lb) {
    int[] temp = a; a = b; b = temp;
    int temp2 = la; la = lb; lb = temp2;
  }
  
  // special case zero elements
  if (la == 0) return null;
  
  // special case one element
  if (la == 1)
    return Arrays.binarySearch(b, a[0]) >= 0 ? a : null;
    
  if (buf == null) buf = new IntBuffer(); else buf.reset();
  intersectSortedIntArrays_recurse(a, b, buf, 0, la, 0, lb);
  return buf.toArray();
}

static void intersectSortedIntArrays_recurse(int[] a, int[] b, IntBuffer buf, int aFrom, int aTo, int bFrom, int bTo) {
  if (aFrom >= aTo || bFrom >= bTo) return; // nothing to do
  
  // start in the middle of a, search this element in b
  int i = (aFrom+aTo)/2;
  int x = a[i];
  int j = Arrays.binarySearch(b, bFrom, bTo, x);

  if (j >= 0) {
    // element found
    intersectSortedIntArrays_recurse(a, b, buf, aFrom, i, bFrom, j);
    buf.add(x);
    intersectSortedIntArrays_recurse(a, b, buf, i+1, aTo, j+1, bTo);
  } else {
    j = -j-1;
    intersectSortedIntArrays_recurse(a, b, buf, aFrom, i, bFrom, j);
    intersectSortedIntArrays_recurse(a, b, buf, i+1, aTo, j, bTo);
  }
}


static int lIntArray(int[] a) {
  return a == null ? 0 : a.length;
}


static class IntBuffer {
  int[] data;
  int size;
  
  IntBuffer() {}
  IntBuffer(int size) { if (size != 0) data = new int[size]; }
  
  void add(int i) {
    if (size >= lIntArray(data))
      data = resizeIntArray(data, Math.max(1, lIntArray(data)*2));
    data[size++] = i;
  }
  
  int[] toArray() {
    return size == 0 ? null : resizeIntArray(data, size);
  }
  
  void reset() { size = 0; }
}

static int[] resizeIntArray(int[] a, int n) {
  if (n == lIntArray(a)) return a;
  int[] b = new int[n];
  arraycopy(a, 0, b, 0, Math.min(lIntArray(a), n));
  return b;
}


static void arraycopy(Object[] a, Object[] b) {
  if (a != null && b != null)
    arraycopy(a, 0, b, 0, Math.min(a.length, b.length));
}

static void arraycopy(Object src, int srcPos, Object dest, int destPos, int n) {
  if (n != 0)
    System.arraycopy(src, srcPos, dest, destPos, n);
}

}