foo.cc: In function 'int main()':
foo.cc:8:9: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
    8 |  freopen("area.in","r",stdin);
      |  ~~~~~~~^~~~~~~~~~~~~~~~~~~~~
foo.cc:9:9: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
    9 |  freopen("area.out","w",stdout);
      |  ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~

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