/in/foo.cc: In function 'void Ins(int, int, int, int)':
/in/foo.cc:17:9: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
  int m=l+r>>1;
        ~^~
/in/foo.cc: In function 'int lower(int, int, int, int, int)':
/in/foo.cc:52:9: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
  int m=l+r>>1;
        ~^~
/in/foo.cc: In function 'int upper(int, int, int, int, int)':
/in/foo.cc:66:9: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
  int m=l+r>>1;
        ~^~
/in/foo.cc: In function 'void DFS(int, int, int)':
/in/foo.cc:80:9: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
  int m=l+r>>1;
        ~^~