formulas – Google sheets, convert value from 1 column to another based on particular data in it

Let’s say I have those values in the column:

w 1

w 2

w 3

I want to convert those values to

1

2

3

in another column.

So basically I need to convert the value “w x” to “x”.
How do I do that?

Another example:
Let’s say I have these values in a column:

World Level 1 (AR 0-19)

World Level 2 (AR 20-24)

World Level 3 (AR 25-29)

I want the result to be

1

2

3