foo.cc: In function 'int main()':
foo.cc:11:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   11 |     scanf("%d",&n);
      |     ~~~~~^~~~~~~~~
foo.cc:12:31: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   12 |     for(int i=1;i<=n;i++)scanf("%d%d",&a[i],&b[i]);
      |                          ~~~~~^~~~~~~~~~~~~~~~~~~~

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