foo.cc: In function 'int main()':
foo.cc:14:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   14 |  scanf("%s%s",a + 1,b + 1);
      |  ~~~~~^~~~~~~~~~~~~~~~~~~~

Found 10 testcases.
[Hydro](https://hydro.ac)提供评测服务