foo.c: In function 'main':
foo.c:5:4: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
    scanf("%d",&n);
    ^~~~~~~~~~~~~~
foo.c:8:7: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
       scanf("%d",&a[i]);
       ^~~~~~~~~~~~~~~~~
foo.c:10:4: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
    scanf("%d",&k);
    ^~~~~~~~~~~~~~

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