foo.cc: In function 'int main()':
foo.cc:21:22: warning: format '%d' expects argument of type 'int', but argument 2 has type 'long long int' [-Wformat=]
   printf("%d\n", a[i]);
                  ~~~~^
foo.cc:8:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d %d %d %d", &n, &m, &p, &q);
  ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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