foo.cc: In function 'int main()':
foo.cc:10:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf ("%d",&n);
  ~~~~~~^~~~~~~~~
foo.cc:14:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
    scanf ("%d",&tmp);
    ~~~~~~^~~~~~~~~~~

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