/in/foo.cc: In function 'node query(int, int, int, int, int)':
/in/foo.cc:78:6: warning: unused variable 'ls' [-Wunused-variable]
  int ls,rs;
      ^~
/in/foo.cc:78:9: warning: unused variable 'rs' [-Wunused-variable]
  int ls,rs;
         ^~
/in/foo.cc: In function 'int main()':
/in/foo.cc:138:6: warning: unused variable 'sum' [-Wunused-variable]
  int sum,l,r,t;
      ^~~