foo.cc: In function 'int main()':
foo.cc:8:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
    8 |  scanf("%d", &n);
      |  ~~~~~^~~~~~~~~~
foo.cc:9:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
    9 |  scanf("%d", &a);
      |  ~~~~~^~~~~~~~~~
foo.cc:11:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   11 |  {scanf("%d", &b);printf("%d ", b);}
      |   ~~~~~^~~~~~~~~~

[Hydro](https://hydro.ac)提供评测服务