/in/foo.cc: In function 'int main()':
/in/foo.cc:7:16: warning: unused variable 'A' [-Wunused-variable]
    7 |         double A,B;
      |                ^
/in/foo.cc:7:18: warning: unused variable 'B' [-Wunused-variable]
    7 |         double A,B;
      |                  ^