foo.cc: In function 'int main()':
foo.cc:71:22: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   71 |                 scanf("%d", &sta.m[i][j] );
      |                 ~~~~~^~~~~~~~~~~~~~~~~~~~~

[Hydro](https://hydro.ac)提供评测服务