Because of reverse thinking, No.4 and No.3 can't die, but No.3 won't give him pearls, and No.2 will die, so he can't get pearls in these stages.
If 1 is analyzed in this way, we know that No.4 has no choice, so if we give him 1, we will certainly win his approval, won't we?
And comrade txdyh 124, according to your answer, No.4 may not agree with the plan of No.3, because he may agree with the plan of No.3 or need not die, so 1 has to pay a pearl to get the support of No.4.