foo.cc: In function 'int main()':
foo.cc:26:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d",&n);m=2;
  ~~~~~^~~~~~~~~
foo.cc:29:9: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
    scanf("%d",&a[i][j]);
    ~~~~~^~~~~~~~~~~~~~~

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

{"receive":"2020-08-10T03:02:24.666Z","handle":"2020-08-10T03:02:24.666Z","cache_start":"2020-08-10T03:02:24.674Z","read_cases":"2020-08-10T03:02:24.791Z","judge":"2020-08-10T03:02:24.798Z","done":"2020-08-10T03:02:25.164Z"}