foo.cc: In function 'int main()':
foo.cc:128:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  128 |   scanf("%d %d", &n, &m);
      |   ~~~~~^~~~~~~~~~~~~~~~~
foo.cc:130:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  130 |     scanf("%d", a + i);
      |     ~~~~~^~~~~~~~~~~~~
foo.cc:135:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  135 |     scanf("%d %d %d", &qsk[0], &qsk[1], &qsk[2]);
      |     ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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