Steps to Reproduce: 1. Run the program 2. Input "new game" 3. Input "4 3 4 4" 4. Input "4 6 4 5" 5. Input "4 4 4 5" 6. Input "4 9 4 8" 7. Input "4 5 4 6" 8. Input "0 9 0 8" 8. Input "4 6 4 7" 8. Input "4 8 4 7" Actual Result: The move "4 8 4 7" is done. Expected Result: The movement is invalid.
*** This bug has been marked as a duplicate of bug 410 ***