  Let $A \cong k\langle X \rangle / I$ be an associative algebra. A finite word
over alphabet $X$ is $I${\it-reducible} if its image in $A$ is a $k$-linear
combination of length-lexicographically lesser words. An {\it obstruction} in a
subword-minimal $I$-reducible word. A {\em cogrowth} function is number of
obstructions of length $\le n$. We show that the cogrowth function of a
finitely presented algebra is either bounded or at least logarithmical. We also
show that an uniformly recurrent word has at least logarithmical cogrowth.
