/in/foo.cc: In function 'int main()':
/in/foo.cc:13:31: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
  freopen("tower.in","r",stdin);
                               ^
/in/foo.cc:14:33: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
  freopen("tower.out","w",stdout);
                                 ^
/in/foo.cc:21:23: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%s",&str1[1]);
                       ^
/in/foo.cc:23:23: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%s",&str2[1]);
                       ^