foo.cc: In function 'int main()':
foo.cc:45:18: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   45 |             scanf("%d%d",&a,&b);
      |             ~~~~~^~~~~~~~~~~~~~
foo.cc:51:18: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   51 |             scanf("%d",&a);
      |             ~~~~~^~~~~~~~~

[Hydro](https://hydro.ac)提供评测服务