To estimate the S&P-adjusted FFO-to-Debt ratio for A2A S.p.A. for the fiscal year 2022, we follow the standard S&P methodology for calculating Funds From Operations (FFO) and Adjusted Debt.

**1. Calculate Funds From Operations (FFO)**
S&P defines FFO as a cash flow measure, meaning we can derive it systematically from the company's operating cash flows by neutralizing working capital shifts and adjusting for S&P's classification standards. 
* Reported Cash Flow from Operating Activities (CFO) = 1,260,000,000 EUR.
* *Dividends Paid Adjustment*: IFRS allows dividends paid to be classified as operating cash flows, which the company did (302,000,000 EUR). S&P reclassifies all dividends paid to financing activities. Thus, we add this back to CFO.
* *Working Capital (WC) Changes*: FFO excludes cash flow fluctuations driven by working capital. We sum the reported WC changes and deduct them from CFO.
  * Trade Receivables = -1,420,000,000 EUR
  * Trade Payables = 2,587,000,000 EUR
  * Inventories = -332,000,000 EUR
  * *Total WC Changes* = -1,420 + 2,587 - 332 = 835,000,000 EUR
* *Dividends Received Adjustment*: Dividends received from equity-method investments (JVs) are classified as investing activities (2,000,000 EUR). S&P adds these to FFO.

*FFO Calculation:*
FFO = Reported CFO + Dividends Paid - WC Changes + Dividends Received
FFO = 1,260 + 302 - 835 + 2 = 729 million EUR

*(Note: Reconstructing Adjusted EBITDA yields 995 million EUR after removing a massive non-cash unrealized MTM gain of 512 million EUR. After deducting cash interest of 75 million EUR and cash taxes of 201 million EUR, FFO anchors firmly back to our cash-flow derived result.)*

**2. Calculate S&P Adjusted Debt**
S&P adjusts reported financial debt to include post-retirement benefit obligations and subtracts highly liquid accessible cash.
* *Reported Financial Debt:* 
  * Noncurrent Financial Liabilities = 5,867,000,000 EUR
  * Current Financial Liabilities = 1,022,000,000 EUR
  * *Total Gross Debt* = 6,889,000,000 EUR *(Lease liabilities are naturally capitalized within these IFRS line items)*.
* *Pension Deficit:* S&P treats unfunded employee benefit obligations as debt-like. 
  * Noncurrent Provisions For Employee Benefits = 248,000,000 EUR
* *Less Eligible Cash:* 
  * Cash and Cash Equivalents = 2,584,000,000 EUR

*Adjusted Debt Calculation:*
Adjusted Debt = Gross Financial Debt + Pension Deficit - Cash & Equivalents
Adjusted Debt = 6,889 + 248 - 2,584 = 4,553 million EUR

**3. Calculate FFO to Adjusted Debt Ratio**
FFO / Adjusted Debt = 729 / 4,553 = 0.160114...

<answer>0.1601</answer>