package ds; 

import java.io.BufferedInputStream; 
import java.io.File;
 import java.io.IOException; 
import java.io.InputStream;
 import java.net.Socket; 
import java.net.URL; 
import java.net.URLConnection; 
import java.nio.file.Files; 

import java.util.NoSuchElementException;

 public final class BinaryInputStream { 
private static final int EOF = -1; // end of file private static final String READING_EMPTY = "Reading from empty input stream"; private BufferedInputStream in; 
// the input stream 
private int buffer;
 // one character buffer 
private int n; 
// number of bits left in buffer
 

 public BinaryInputStream() {
 in = new BufferedInputStream(System.in); fillBuffer(); 
} 

 private void fillBuffer() { 
try { buffer = in.read(); n = 8; } catch (IOException e) { System.err.println("EOF : " + e.getMessage()); buffer = EOF; n = -1; } } 

 public boolean isEmpty() { return buffer == EOF; } 

public char readChar() { 
if (isEmpty()) throw new NoSuchElementException(READING_EMPTY); // special case when aligned byte 
if (n == 8) {
 int x = buffer; 
fillBuffer();
 return (char) (x & 0xff); 
} 
// combine last N bits of current buffer with first 8-N bits of new buffer 
int x = buffer; x <<= 8 - n; 
int oldN = n; // flagged for PrematureDeclaration

fillBuffer();
 if (isEmpty()) throw new NoSuchElementException(READING_EMPTY); 
n = oldN; 
x |= buffer >>> n;
 return (char) (x & 0xff); 
// the above code doesn't quite work for the last character if N = 8 
// because buffer will be -1 
} 

  }