字符窜初学2（0.5）
You cannot submit for this problem because the contest is ended. You can click "Open in Problem Set" to view this problem in normal mode.
说明
任意输入一个字符窜（小于100位），输出字符窜里有多少个字符‘a’。
appletoeat
2
You cannot submit for this problem because the contest is ended. You can click "Open in Problem Set" to view this problem in normal mode.
任意输入一个字符窜（小于100位），输出字符窜里有多少个字符‘a’。
appletoeat
2