foo.cc: In function 'int main()':
foo.cc:11:7: warning: ignoring return value of 'char* fgets(char*, int, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
  fgets(s1,10000,stdin);
  ~~~~~^~~~~~~~~~~~~~~~
foo.cc:12:7: warning: ignoring return value of 'char* fgets(char*, int, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
  fgets(s2,10000,stdin);
  ~~~~~^~~~~~~~~~~~~~~~