--java.lang.Object
 --java.io.InputStream

public abstract class InputStream implements Closeable

public interface Closeable extends AutoCloseable {
  public void close() throws IOException;
}

private static final int MAX_SKIP_BUFFER_SIZE = 2048;

private static final int DEFAULT_BUFFER_SIZE = 8192;

private static final int MAX_BUFFER_SIZE = Integer.MAX_VALUE - 8;

  public abstract int read() throws IOException;

  public int read(byte b[]) throws IOException {
    return read(b, 0, b.length);
  }
  public int read(byte b[], int off, int len) throws IOException {
    if (b == null) {
      throw new NullPointerException();
    } else if (off < 0 || len < 0 || len > b.length - off) {
      throw new IndexOutOfBoundsException();
    } else if (len == 0) {
      return 0;
    }

    int c = read();
    if (c == -1) {
      return -1;
    }
    b[off] = (byte)c;

    int i = 1;
    try {
      for (; i < len ; i++) {
        c = read();
        if (c == -1) {
          break;
        }
        b[off + i] = (byte)c;
      }
    } catch (IOException ee) {
    }
    return i;
  }

  public byte[] readAllBytes() throws IOException {
    byte[] buf = new byte[DEFAULT_BUFFER_SIZE];
    int capacity = buf.length;
    int nread = 0;
    int n;
    for (;;) {
      while ((n = read(buf, nread, capacity - nread)) > 0)
        nread += n;
      if (n < 0)
        break;
      if (capacity <= MAX_BUFFER_SIZE - capacity) {
        capacity = capacity << 1;
      } else {
        if (capacity == MAX_BUFFER_SIZE)
          throw new OutOfMemoryError("Required array size too large");
        capacity = MAX_BUFFER_SIZE;
      }
      buf = Arrays.copyOf(buf, capacity);
    }
    return (capacity == nread) ? buf : Arrays.copyOf(buf, nread);
  }

  public int readNBytes(byte[] b, int off, int len) throws IOException {
    Objects.requireNonNull(b);
    if (off < 0 || len < 0 || len > b.length - off)
      throw new IndexOutOfBoundsException();
    int n = 0;
    while (n < len) {
      int count = read(b, off + n, len - n);
      if (count < 0)
        break;
      n += count;
    }
    return n;
  }

public int available() throws IOException {
    return 0;
  }

  public long skip(long n) throws IOException {

    long remaining = n;
    int nr;

    if (n <= 0) {
      return 0;
    }

    int size = (int)Math.min(MAX_SKIP_BUFFER_SIZE, remaining);
    byte[] skipBuffer = new byte[size];
    while (remaining > 0) {
      nr = read(skipBuffer, 0, (int)Math.min(size, remaining));
      if (nr < 0) {
        break;
      }
      remaining -= nr;
    }

    return n - remaining;
  }

public void close() throws IOException {}

  public long transferTo(OutputStream out) throws IOException {
    Objects.requireNonNull(out, "out");
    long transferred = 0;
    byte[] buffer = new byte[DEFAULT_BUFFER_SIZE];
    int read;
    while ((read = this.read(buffer, 0, DEFAULT_BUFFER_SIZE)) >= 0) {
      out.write(buffer, 0, read);
      transferred += read;
    }
    return transferred;
  }

  public boolean markSupported() {
    return false;
  }

public synchronized void mark(int readlimit) {}

  public synchronized void reset() throws IOException {
    throw new IOException("mark/reset not supported");
  }