A company manufactures $x$ units of a certain product. The cost $C$, in dollars, of manufacturing $x$ units is given by the formula $C=1000+25x$. The revenue $R$, in dollars, from selling $x$ units is given by $R=50x$. The profit $P$ is calculated as $P=R-C$. If the company wants the profit to be no more than $1500+5x$ dollars, what is the greatest integer number of units, $x$, that can be manufactured?