foo.cc: In function 'int main()':
foo.cc:7:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d",&n);
  ~~~~~^~~~~~~~~
foo.cc:9:9: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  { scanf("%d%d%d%d", &a[i],&b[i],&x[i],&y[i]);
    ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
foo.cc:12:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d%d",&X,&Y);
  ~~~~~^~~~~~~~~~~~~~

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