/in/foo.cc: In function 'int main()':
/in/foo.cc:16:6: warning: unused variable 'x' [-Wunused-variable]
  int x,y,a[101],n;
      ^
/in/foo.cc:16:8: warning: unused variable 'y' [-Wunused-variable]
  int x,y,a[101],n;
        ^