Extract certain text dependant on number of characters in text

Hi All,

New to posting on here so here's my first query;

I have a column of data that is made up of alpha and numeric values, I need to extract either the first 3 charcters if the Character length is 7 characters long, or the first 4 characters if it is 8 characters in length into Column B.
Eg;

Column A contains the folowing;
T03HD0A (From this I need T03 in column B)
T03EF0A (From this I need T03 in column B)
T01GA0A (From this I need T01 in column B)
XW2AAA0A (From this I need XW2A in column B)
XW2BAA0A (From this I need XW2B in column B1)

I have tried LEFT and IF but can't seem to ocmbine tHE two to get the result I want.

Any help gratefully received.

=IF(LEN(A1)=7,LEFT(A1,3),LEFT(A1,4))

put in B1 and dragged down

Many thanks Azumi and Sixthsense for your quick replies both have solved my problem!