foo.cc: In function 'int main()':
foo.cc:9:6: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
 scanf("%d%d%d", &n, &m, &p);
 ~~~~~^~~~~~~~~~~~~~~~~~~~~~
foo.cc:12:16: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
 int x, y; scanf("%d%d", &x, &y);
           ~~~~~^~~~~~~~~~~~~~~~

[Hydro](https://hydro.ac)提供评测服务