/in/foo.cc: In function 'int main()':
/in/foo.cc:11:13: warning: unused variable 'y' [-Wunused-variable]
  int x; int y;
             ^
/in/foo.cc:9:13: warning: 'a[0]' is used uninitialized in this function [-Wuninitialized]
  int b = a[0];
             ^