The figure shows a fixed circle $C_1$ with equation $(x-1)^2+y^2=1$ and a shrinking circle $C_2$ with radius $r$ and center the origin. $P$ is the point $(0,r)$, $Q$ is the upper point of the intersection of the two circles, and $R$ is the point of intersection of the line $PQ$ and the x-axis. What happens to the x-coordinate of $R$ as $C_2$ shrinks, that is, as $r \to 0^+$?

The x-coordinate of $R \to \;$
If the answer is infinity or negative infinity, enter $I$ or $-I$ as appropriate. If the limit does not exist, type DNE.