foo.cc: In function 'int main()':
foo.cc:24:20: warning: format '%d' expects argument of type 'int*', but argument 2 has type 'long int*' [-Wformat=]
  scanf("%d%d",&m,&n);
               ~~   ^
foo.cc:24:20: warning: format '%d' expects argument of type 'int*', but argument 3 has type 'long int*' [-Wformat=]
foo.cc:28:20: warning: format '%d' expects argument of type 'int*', but argument 2 has type 'long int*' [-Wformat=]
   scanf("%d",&ch[i]);
              ~~~~~~^
foo.cc:31:2: error: 'prin' was not declared in this scope
  prin
  ^~~~
foo.cc:31:2: note: suggested alternative: 'main'
  prin
  ^~~~
  main
foo.cc:31:2: error: expected '}' at end of input
foo.cc:24:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d%d",&m,&n);
  ~~~~~^~~~~~~~~~~~~~
foo.cc:28:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d",&ch[i]);
   ~~~~~^~~~~~~~~~~~~

自豪的采用 HydroJudge 进行评测(github.com/hydro-dev/HydroJudge)