foo.c: In function 'main':
foo.c:6:6: warning: unused variable 'a' [-Wunused-variable]
  int a[n + 1];
      ^
foo.c:5:2: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d%d", &n, &k);
  ^~~~~~~~~~~~~~~~~~~~~
foo.c:10:2: warning: 's' may be used uninitialized in this function [-Wmaybe-uninitialized]
  printf("%d", s+1);
  ^~~~~~~~~~~~~~~~~

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