foo.cc: In function 'int main()':
foo.cc:5:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d %d",&n,&k);
  ~~~~~^~~~~~~~~~~~~~~
foo.cc:7:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d",&x[i]);
   ~~~~~^~~~~~~~~~~~

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