foo.cc: In function 'int main()':
foo.cc:25:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   25 |  scanf("%d %d %d %d %d", &a, &b, &k, &n, &m);
      |  ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Found 5 testcases.
[Hydro](https://hydro.ac)提供评测服务