为给定的输入语法，建立一个相应的解析树。
以下输入语法: 
<expression> ::= <expression> + <term> | <expression> - <term> | <term>
<term> ::= <term> * <factor> | <term> / <factor> | <factor>
<factor> ::= ( <expression> ) | <number>
<number> ::= [0-9]+
输入字符串: 2 + 3 * (5 - 2)
```
              expression
                  |
               expression (+)
                  |
               /      \
             term     factor
              |         |
             term (*)  expression
              |         |
           /      \   /      \
       factor   number  term  factor
         |         |     |       |
        number     2   factor  expression
                     |       /     \
                     |   factor   term (-)
                     |     |        |
                     |  number  factor
                     |             |
                     |             number
                     |               |
                     3               5
```

这是输入字符串 "2 + 3 * (5 - 2)" 的相应解析树。