foo.cc: In function 'int main()':
foo.cc:12:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   12 |  scanf("%d%d%d",&K,&V,&n);
      |  ~~~~~^~~~~~~~~~~~~~~~~~~
foo.cc:14:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   14 |   scanf("%d%d",&v[i],&w[i]);
      |   ~~~~~^~~~~~~~~~~~~~~~~~~~

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