foo.cc: In function 'int main()':
foo.cc:21:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   21 |  scanf("%lld", &n);
      |  ~~~~~^~~~~~~~~~~~
foo.cc:22:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   22 |  scanf("%lld %lld", &A, &B);
      |  ~~~~~^~~~~~~~~~~~~~~~~~~~~
foo.cc:24:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   24 |   scanf("%lld %lld", &jb[i].a, &jb[i].b);
      |   ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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