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 BufferedImage imageFromFunction(int w, IF2_Int f) { return imageFromFunction(w, w, f); }
static BufferedImage imageFromFunction(int w, int h, IF2_Int f) {
  int[] pixels = new int[w*h];
  int i = 0;
  for (int y = 0; y < h; y++)
    for (int x = 0; x < w; x++)
      pixels[i++] = f.get(x, y);
  return intArrayToBufferedImage(pixels, w, h);
}
// from: https://stackoverflow.com/questions/14416107/int-array-to-bufferedimage
// pixels are RGB pixels
static BufferedImage intArrayToBufferedImage(int[] pixels, int w, int h) {
  int[] bitMasks = new int[]{0xFF0000, 0xFF00, 0xFF, 0xFF000000};
  SinglePixelPackedSampleModel sm = new SinglePixelPackedSampleModel(DataBuffer.TYPE_INT, w, h, bitMasks);
  DataBufferInt db = new DataBufferInt(pixels, pixels.length);
  WritableRaster wr = Raster.createWritableRaster(sm, db, new Point());
  return new BufferedImage(ColorModel.getRGBdefault(), wr, false, null);
}




static interface IF2_Int {
  int get(int a, int b);
}

}