foo.cc: In function 'int main()':
foo.cc:18:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   18 |  scanf("%d%d%d", &n, &m, &k);
      |  ~~~~~^~~~~~~~~~~~~~~~~~~~~~
foo.cc:20:30: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   20 |  for(i = 1; i <= m; i++)scanf("%d%d%d", &fuk[i].a, &fuk[i].b, &fuk[i].c);
      |                         ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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