foo.cc: In function 'int main()':
foo.cc:14:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   14 |   scanf("%d%d%d%d",&ax,&ay,&bx,&by);
      |   ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~

Found 5 testcases.
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