foo.cc: In function 'int main()':
foo.cc:64:6: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   64 | scanf( "%d%d" , &n , &m ) ;
      | ~~~~~^~~~~~~~~~~~~~~~~~~~
foo.cc:69:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   69 | int x ; scanf( "%d" , &x ) ;
      |         ~~~~~^~~~~~~~~~~~~
foo.cc:76:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   76 | int x ; scanf( "%d" , &x ) ;
      |         ~~~~~^~~~~~~~~~~~~

[Hydro](https://hydro.ac)提供评测服务