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Friend

Friend

#描述#
Friendnumber is defined recursively as follows.
(1) numbers 1 and 2 are friend number;
(2) if a and b are friend numbers, so is ab+a+b;
(3) only the numbers defined in (1) and (2) are friend number.
Now your task is to judge whether an integer is a friend number.

#格式#
##输入格式##
There are several lines in input, each line has a nonnegative integer a (0&lt=a&lt=2^30)。

##输出格式##
For the number a on each line of the input, if a is a friend number, output “YES!”, otherwise output “NO!”.

#样例1#
##样例输入1##

3
13121
12131

##样例输出1##

YES!
YES!
NO!

#限制#
1000ms
32768KB

#提示#

#来源#

信息

ID
1324
难度
5
分类
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