Define the edit distance between two strings x and y of length n and m, respectively, to be the number of edits that it takes to change x into y. an edit consists of a character insertion, a character deletion, or a character replacement. for example, the strings "algorithm" and "rhythm" have an edit distance 6. design an o(nm)-time algorithm for computing the edit distance between x and y.

there is no universally accepted definition of art. although commonly used to describe something of beauty, or a skill which produces an aesthetic result, there is no clear line in principle between (say) a unique piece of handmade sculpture, and a mass-produced but visually attractive item. we might say that art requires thought - some kind of creative impulse - but this raises more questions: for example, how much thought is required? if someone flings paint at a canvas, hoping by this action to create a work of art, does the result automatically constitute art?