The smallest distance between the origin and a point on the parabola $y=x^2-5$ can be expressed as $\sqrt{a}/b$, where $a$ and $b$ are positive integers, and $a$ is not divisible by the square of any prime.  Find $a+b$.
<|im_start|>system
You are a helpful assistant.<|im_end|>
<|im_start|>user
The smallest distance between the origin and a point on the parabola $y=x^2-5$ can be expressed as $\sqrt{a}/b$, where $a$ and $b$ are positive integers, and $a$ is not divisible by the square of any prime.  Find $a+b$.
Please reason step by step, and put your final answer within \boxed{{}}.<|im_end|>
<|im_start|>assistant

user
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The smallest distance between the origin and a point on the parabola $y=x^2-5$ can be expressed as $\sqrt{a}/b$, where $a$ and $b$ are positive integers, and $a$ is not divisible by the square of any prime.  Find $a+b$.
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