Difficult# Intersecting Chords

SATMAT-C8A1TI

$CE$ and $AD$ are the lengths of chords of a circle that intersect at point $B$, as shown in the figure above.

If $CB$ is $1$ unit greater than $AB$, $CB$ is $4$ units less than $BD$, and $EB$ is $2$ units greater than $CB$, then what is the measure o$AD$?

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