/in/foo.cc: In function 'void build(int, int, int)':
/in/foo.cc:29:11: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
  int mid=l+r>>1;
          ~^~
/in/foo.cc: In function 'void update(int, int, int, int)':
/in/foo.cc:38:11: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
  int mid=l+r>>1;
          ~^~