cannot resolve circular reference Cell AP35

I found the circular reference! Once I mapped out the cell formulas showing cell number and "formulas derived from dependencies" with those cells, I was able to determine that formulas calculating cell L and Z were the culprit. Upon further investigation, I had the formula in cell L for IRA End Balance pulling the IRA withdrawal from CURRENT YEAR instead of prior year. Once I compared 401K end balance and roth ira end balance formulas, I was able to see the error. Praise the Lord! Even with a complicated set of formulas as this workbook is, it all comes down to Core Logic. Your logic must make sense! Thanks for your help.
HR
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This post is in reference to one called "need retirement withdrawal posted on 4/11." I resolved that one as I reworked some formulas and have most of the logic down. Basically, I have most all of the retirement calculator logic worked out so it does the following:
In years where Annual Income<Retirement Goal a retirement Withdrawal is required. That retirement withdrawal will pull 4% from 401K, IRA and Roth IRA end balances respectively. Any additional withdrawals needed to make up the shortfall will be pulled from the investment account with the largest balance. I have added columns with formulas so it is easier to see the logic in cells AN-AW. I have adjusted the formulas so if there are no withdrawals (in years where annual income> retirement goal), those monies are not displayed. The problem is with cell AP35 for computing max IRA withdrawal. I am set with computing max 401K and max Roth IRA Withdrawal. But this is giving me a circular reference error as the max IRA withdrawal is calculated as (.04* ira end bal) and I have the end balance adding back in any withdrawals. I found that I had to do that in order to "establish" the beginning balance for the next year. It should equal end balance from prior year minus any withdrawals to give you a beginning balance for the next year.

I know I am in the home stretch with these formulas and would appreciate any help to finish it up.

Max IRA Withdrawal is AP35=IF(AB35<0,L35*0.04,0)*(-1)
End IRA Bal is L35=IF(B35>Retire_Age+Yrs_InRetire,"",SUM(L34,J35,K35,Z35))
IRA Withdrawal is Z35=IF(B35>Retire_Age+Yrs_InRetire,0,MAX(IF(ISNUMBER(AP35+AU35),AP35+AU35)))
AU35=Additional IRA Withdrawal

I simply do not know how to construct the logic for these formulas any other way.

Thanks
HR