fix math display

README.md

@@ -62,7 +62,7 @@ The dataset supports two programming languages, Python and Java, and contains tw
 - `cff`: short for `cross_file_first`, where the cross-file module in next line is first used in the current file.
 - `cfr`: short for `cross_file_random`, where the cross-file module in next line is not first used in the current file.
 
-For each setting, we provide two levels of difficulty: `easy` and `hard`. Suppose the number of code snippets in the context is <math>k</math>, then for the `easy` subset, we have <math>5 \leq k < 10</math>, while for the `hard` subset, we have <math>k \geq 10</math>.
+For each setting, we provide two levels of difficulty: `easy` and `hard`. Suppose the number of code snippets in the context is \(k\), then for the `easy` subset, we have \(5 \leq k < 10\), while for the `hard` subset, we have \(k \geq 10\).
 
 So, the specific information of each split is as follows: