foo.cc: In function 'int main()':
foo.cc:25:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   25 |     scanf("%d", &n);
      |     ~~~~~^~~~~~~~~~
foo.cc:26:23: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   26 |     rep(i, 1, n) scanf("%d%d", &a[i].l, &a[i].w);
      |                  ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~

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