Java (Sun-JDK-1.8.0_51)
/* package whatever; // don't place package name! */
import java.io.*;
/* Name of the class has to be "Main" only if the class is public. */
class Ideone
{
public static void main (String[] args) throws java.lang.Exception
{
BufferedReader r = new BufferedReader (new InputStreamReader (System.in));
String s;
while (!(s=r.readLine()).startsWith("42")) System.out.println(s);
}
}
Doubtful Deer