foo.cc: In function 'int main()':
foo.cc:36:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   36 |     scanf("%d%d", &n, &m);
      |     ~~~~~^~~~~~~~~~~~~~~~
foo.cc:40:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   40 |         scanf("%d%d", &u, &v);
      |         ~~~~~^~~~~~~~~~~~~~~~
foo.cc:45:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   45 |         scanf("%d", h + i);
      |         ~~~~~^~~~~~~~~~~~~
foo.cc:47:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   47 |         scanf("%d", s + i);
      |         ~~~~~^~~~~~~~~~~~~
foo.cc:50:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   50 |         scanf("%s %d %d", op, &x, &y);
      |         ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~

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