foo.cc: In function 'int main()':
foo.cc:23:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d",&N);
  ~~~~~^~~~~~~~~
foo.cc:26:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d",&op);
   ~~~~~^~~~~~~~~~
foo.cc:28:9: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
    scanf("%d %d %d",&x,&y,&xx);
    ~~~~~^~~~~~~~~~~~~~~~~~~~~~
foo.cc:32:9: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
    scanf("%d %d %d %d",&x,&y,&xx,&yy);
    ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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