foo.cc: In function 'int main()':
foo.cc:29:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   29 |  scanf("%d%d%d",&n,&m,&p);
      |  ~~~~~^~~~~~~~~~~~~~~~~~~
foo.cc:31:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   31 |   scanf("%d%d",&val[i],&w[i]);
      |   ~~~~~^~~~~~~~~~~~~~~~~~~~~~
foo.cc:34:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   34 |   scanf("%d%d",&u,&v);
      |   ~~~~~^~~~~~~~~~~~~~

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