求s=a+a aa+aaaa+aa...a的值，其中a是一个数字。例如2+22+222+2222+22222(此时共有5个数相加)，几个数相加有键盘控制。-S = a+aa+aaa+aaaa+aa ... a demand value, where a is a number. For example 2+22+222+2222+22222 (at this time the number of the sum total of five), a few numbers together with a keyboard control.