remove

Author: lrvideckis

library/contest/README.md

@@ -14,11 +14,6 @@ for policy base DS:
 #include <bits/extc++.h>
 ```
 
-for -std=c++17
-```
-#define ssize(x) (int)(x).size()
-```
-
 don't use cin for doubles/floats, it's slow, read into string, then convert to double/float
 - [C++ tips and tricks](https://codeforces.com/blog/entry/74684)
 - invokes RTE (Run Time Error) upon integer overflow