  A word $u$ is a subsequence of another word $w$ if $u$ can be obtained from
$w$ by deleting some of its letters. The word $w$ with alph$(w)=\Sigma$ is
called $k$-subsequence universal if the set of subsequences of length $k$ of
$w$ contains all possible words of length $k$ over $\Sigma$. We propose a
series of efficient algorithms computing the minimal number of edit operations
(insertion, deletion, substitution) one needs to apply to a given word in order
to reach the set of $k$-subsequence universal words.
