foo.cc: In function 'int main()':
foo.cc:97:35: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         for(int i=0;i<9;i++) scanf("%d",&in[i]);
                              ~~~~~^~~~~~~~~~~~~

[Hydro](https://hydro.ac)提供评测服务