View Compilation Error

0_0_39631033_4953.cpp: In function 'void _sol()':
0_0_39631033_4953.cpp:338:14: error: 'fast_output' is not a member of 'std'; did you mean 'fast_output'?
  338 | #define cout fast_output
      |              ^~~~~~~~~~~
0_0_39631033_4953.cpp:497:8: note: in expansion of macro 'cout'
  497 |   std::cout << "Case #" << Testcnt << ": " << f[0] << '\n';
      |        ^~~~
0_0_39631033_4953.cpp:336:3: note: 'fast_output' declared here
  336 | } fast_output;
      |   ^~~~~~~~~~~