/in/foo.cc: In function 'void build(int, int, int)':
/in/foo.cc:25:12: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
  int m = l + r >> 1;
          ~~^~~
/in/foo.cc: In function 'void update(int, int, int, int, int)':
/in/foo.cc:35:12: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
  int m = l + r >> 1;
          ~~^~~
/in/foo.cc: In function 'node query(int, int, int, int, int)':
/in/foo.cc:43:12: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
  int m = l + r >> 1, max1;
          ~~^~~
/in/foo.cc:43:22: warning: unused variable 'max1' [-Wunused-variable]
  int m = l + r >> 1, max1;
                      ^~~~
/in/foo.cc:44:7: warning: unused variable 's1' [-Wunused-variable]
  node s1, s2;
       ^~
/in/foo.cc:44:11: warning: unused variable 's2' [-Wunused-variable]
  node s1, s2;
           ^~
/in/foo.cc: In function 'int main()':
/in/foo.cc:59:9: warning: unused variable 'j' [-Wunused-variable]
  int i, j, n, m, o, a, b, c;
         ^
/in/foo.cc:59:27: warning: unused variable 'c' [-Wunused-variable]
  int i, j, n, m, o, a, b, c;
                           ^