/in/foo.cc: In function 'void Ins(int, int, int, int)':
/in/foo.cc:18:9: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
  int m=l+r>>1;
        ~^~
/in/foo.cc: In function 'int Ask(int, int, int, int, int)':
/in/foo.cc:26:9: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
  int m=l+r>>1;
        ~^~
/in/foo.cc: In function 'void DFS(int, int, int)':
/in/foo.cc:38:9: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
  int m=l+r>>1;
        ~^~