In circle $\omega$ with radius 7 centered at $O$, point $P$ lies outside $\omega$ such that $OP = 25$. Tangents $PA$ and $PB$ are drawn to the circle from $P$ such that they touch the circle at points $A$ and $B$ respectively. Another circle $\gamma$ is inscribed in the quadrilateral $OPAB$. Find the radius of circle $\gamma$. Let's think step by step and output the final answer within \boxed{}.
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