foo.cc: In function 'int main()':
foo.cc:17:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   17 |     scanf("%d",&n);
      |     ~~~~~^~~~~~~~~
foo.cc:19:12: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   19 |       scanf("%d%d",&a[i].l,&a[i].r);
      |       ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~

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