answer.code:19:11: warning: use of ‘auto’ in parameter declaration only available with ‘-std=c++20’ or ‘-fconcepts’
   19 | void cmin(auto &a,auto b){a=min(a,b);}
      |           ^~~~
answer.code:19:19: warning: use of ‘auto’ in parameter declaration only available with ‘-std=c++20’ or ‘-fconcepts’
   19 | void cmin(auto &a,auto b){a=min(a,b);}
      |                   ^~~~
answer.code:20:11: warning: use of ‘auto’ in parameter declaration only available with ‘-std=c++20’ or ‘-fconcepts’
   20 | void cmax(auto &a,auto b){a=max(a,b);}
      |           ^~~~
answer.code:20:19: warning: use of ‘auto’ in parameter declaration only available with ‘-std=c++20’ or ‘-fconcepts’
   20 | void cmax(auto &a,auto b){a=max(a,b);}
      |                   ^~~~
answer.code:163:34: warning: use of ‘auto’ in parameter declaration only available with ‘-std=c++20’ or ‘-fconcepts’
  163 |         empty_cerr_t& operator<<(auto x) {
      |                                  ^~~~
answer.code: In function ‘void work()’:
answer.code:286:39: error: ‘__acrt_iob_func’ was not declared in this scope
  286 |                 stdin_buf=in_buffer_t(__acrt_iob_func(0));
      |                                       ^~~~~~~~~~~~~~~