from /b/ plz Help

okay I am a starting cs major and I have one little snag

I get most of java so far but have to do:

is some number a multiple of 50

Now I divide the number by 50, Number/50 but dont know what to do after that.  This is due in a noon Saturday and I woke up early to do it can you guys help

package org.4chan.dis.prog.1222505434;

public class Idiots extends Object {
  pubic static void main(int argc, char* argv) {
    int input = Integer.parseInt(argv[1]);
    if (isMultipleOf50(input)) {
      std::cout << " Yes";
    } else {
      throw new IllegalArgumentException("No");
    }
  }

  /* Implemented natively using JNI for performance reasons */
  private static volatile synchronized native void strictfp boolean isMultipleOf50();
}