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。

-Find s = a+ aa+ aaa+ aaaa+ aa ... a value, where a is a number. For example, 2+22+222+2222+22222 (in this case the sum total of the number 5), a few numbers together with the keyboard controls.