/in/foo.cc: In function 'int main()':
/in/foo.cc:40:10: warning: unused variable 'p' [-Wunused-variable]
  int i,j,p,q;
          ^
/in/foo.cc:40:12: warning: unused variable 'q' [-Wunused-variable]
  int i,j,p,q;
            ^