Using ABS Correctly

Hi community

Below is a formula that I am using that combines Index and Match.

In a tab called CTA, if a number is negative such as -$250,000, it would take that number and make is positive


=ABS(INDEX(CTA!$AC$14:$AC$1206,(MATCH('MI Reports'!$B3,CTA!$E$14:$E$1206,0))))

There are instances when the number in CTA tab is positive and I would like that to be shown as negative
Question:

How can I modify the above formula to factor, if the number is negative, make it positive, but if the number is positive, make it negative?




Thanks.