foo.cc: In function 'int merge(int, int)':
foo.cc:11:1: warning: no return statement in function returning non-void [-Wreturn-type]
   11 | }
      | ^
foo.cc: In function 'int main()':
foo.cc:13:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   13 |     scanf("%d%d", &n, &k);
      |     ~~~~~^~~~~~~~~~~~~~~~
foo.cc:16:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   16 |         scanf("%d%d%d", &p, &x, &y);
      |         ~~~~~^~~~~~~~~~~~~~~~~~~~~~

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