foo.c: In function 'main':
foo.c:15:11: warning: format '%d' expects argument of type 'int *', but argument 2 has type 'long long int *' [-Wformat=]
   scanf("%d",&a[i]);
          ~^  ~~~~~
          %lld
foo.c:12:2: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d %d",&n,&k);
  ^~~~~~~~~~~~~~~~~~~~
foo.c:15:3: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d",&a[i]);
   ^~~~~~~~~~~~~~~~~