If the fourth order of Western Cuckooland dictator was '-2', then the number of warheads by the end of 4th month would have been 2, 5th — 0, that is less than in Eastern Cuckooland. The answer is not '0' because it is not the minimal value. Order '-1' is OK. Maybe you should try drawing imaginary lines that will show you how much warheads there will be in Eastern Cuckooland according to every order of its leader to understand how we get the sample.
