foo.cc: In function 'int Pshdwn(int, int, int)':
foo.cc:50:21: warning: suggest parentheses around '-' inside '>>' [-Wparentheses]
   50 |         int mid=l+(r-l>>1);
      |                    ~^~
foo.cc: In function 'void Bd(int, int, int)':
foo.cc:65:21: warning: suggest parentheses around '-' inside '>>' [-Wparentheses]
   65 |         int mid=l+(r-l>>1);
      |                    ~^~

[Hydro](https://hydro.ac)提供评测服务