foo.cpp: In function 'void build(int, int, int)':
foo.cpp:26:11: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
  int mid=l+r>>1;
          ~^~
foo.cpp: In function 'void add(int, int, int, int, int, int)':
foo.cpp:47:11: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
  int mid=l+r>>1;
          ~^~
foo.cpp: In function 'int query(int, int, int, int, int)':
foo.cpp:55:11: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
  int mid=l+r>>1,num=-2147483647,tmp;
          ~^~