/in/foo.cc: In function 'int main()':
/in/foo.cc:41:32: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
  freopen("puzzle.in","r",stdin);
                                ^
/in/foo.cc:42:34: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
  freopen("puzzle.out","w",stdout);
                                  ^
/in/foo.cc:52:28: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
    scanf("%d %d\n",&rr,&cc);
                            ^
/in/foo.cc:57:21: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
      scanf("%c",&ch);
                     ^
/in/foo.cc:60:16: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("\n");
                ^