foo.cc: In function 'int main()':
foo.cc:47:8: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
   47 | freopen("in.txt","r",stdin);
      | ~~~~~~~^~~~~~~~~~~~~~~~~~~~
foo.cc:48:6: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   48 | scanf("%d%d%d",&m,&n,&k);
      | ~~~~~^~~~~~~~~~~~~~~~~~~
foo.cc:51:6: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   51 | scanf("%d%d",&t1,&t2);
      | ~~~~~^~~~~~~~~~~~~~~~

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