How to find Gaussian beam waist?

To find the Gaussian beam waist ω0, is it just 2*pi*wavelength?
Probably not but I know the Rayleigh range is $\frac{\pi \omega_0^2}{\lambda}$
But I'm only given power, lambda, and 1/e2 diameter. I need either w0 or z0 but I don't have either one of them.
I also know that w0 is where the intensity goes down to 1/e2 but can't find the formula.

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Update: never mind got it.
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