foo.c: In function 'main':
foo.c:6:2: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
  scanf ("%d",&m);
  ^~~~~~~~~~~~~~~
foo.c:9:8: warning: 'n' may be used uninitialized in this function [-Wmaybe-uninitialized]
   n = n*10 + m%10;
       ~^~~

[Hydro](https://hydro.ac)提供评测服务