Research studies show that there are some fundamental (1) between men and women in their attitudes to (2) matters. Women are far more likely to save for their children’s (3) and to save up to buy a (4) . Men tend to save for a (5) , and for their (6) . But in fact the need for women to save for their old age is far (7) than for men. Throughout the world, women are likely to live many years (8) than men. Furthermore it is the (9) women who will most often have to look after the children and thus they need more (10) to look after not just themselves but others. Women today need to look ahead, think ahead, not wait until they’re under (11) .
A number of (12) have been set up to help them do this. Some educational institutions offer night (13) in Money (14) . They can be given (15) on different ways of saving. It is usually advised that at least (16) of a person’s savings should be in low-risk investments but for the rest, (17) advisors often advise taking some (18) risks. Initiatives such as this can give women the economic (19) and knowledge they need for a comfortable, (20) retirement.

设输入元素为1、2、3、P和A，入栈次序为123PA，元素经过栈后到达输出序列，当所有元素均到达输出序列后，有哪些序列可以作为高级语言的变量名？