import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
public class Main {
/**
* Read input from input stream and write it to output stream
* until there is no more input from input stream.
*
* @param is input stream the input stream to read from.
* @param os output stream the output stream to write to.
* @param buf the byte array to use as a buffer
*/
public static void flow( InputStream is, OutputStream os, byte[] buf )
throws IOException {
int numRead;
while ( (numRead = is.read(buf) ) >= 0) {
os.write(buf, 0, numRead);
}
}
}