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Time Limit: 2 s Memory Limit: 16 MB Total points: 100

#22824. Cowfix

Statistics

表达式通常使用中缀记法,二元运算符位于操作数之间,如 1+2 或 7*(5-3)。前缀记法中运算符在操作数前,如 + 1 2 或 * 7 - 5 3。后缀记法中运算符在后,如 1 2 + 或 7 5 3 - *。前缀与后缀记法不用括号。

Farmer John 的奶牛经常混合这三种记法。它们用 cowfix 写表达式,只用一位数字和二元运算符 +、-。表达式可按中缀、前缀、后缀规则的任意混合解释。例如 +54+-82 至少有两种求值方式:

+ 5 4 + - 8 2 = 9 + - 8 2 = 9 + 6 = 15
+ 5 4 + - 8 2 = + 9 - 8 2 = + 1 2 = 3

表达式 9-4+3 可得到 $2$ 和 $8$。给定 cowfix 表达式,求其可能得到的不同数值的数量。保证输入是语法合法的 cowfix 表达式。

输入格式

一个至多 80 个字符、不含空格的字符串。

输出格式

一行输出不同可能数值的数量。

样例

输入格式 1

+54+-82

输出格式 1

2

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