To determine the FFO / Net Debt ratio for ENI S.P.A. at the end of 2022 based on standard S&P (Standard & Poor's) methodology, we must calculate the Funds From Operations (FFO) and the S&P Adjusted Net Debt using the reported figures.

**1. Funds From Operations (FFO)**
S&P defines FFO as Operating Cash Flow (OCF) before changes in working capital. 
*   **Operating Cash Flow (OCF):** "Cash Flows From Used In Operating Activities" = €17,460 million.
*   **Working Capital Changes:** To find the cash effect of working capital, we analyze the reported components: Inventories (-€2,528m), Trade Receivables (-€1,036m), Trade Payables (+€2,284m), Provisions (+€2,028m), and Other assets/liabilities (-€2,027m). This indicates a net cash outflow (use of cash) of approximately €1,279 million. 
*   **FFO** = OCF - Working Capital Cash Flow = €17,460m - (-€1,279m) = **€18,739 million**.

**2. S&P Adjusted Net Debt**
S&P makes several key adjustments to debt, especially for Oil & Gas majors, adding operating lease liabilities, unfunded pension obligations, and Asset Retirement Obligations (AROs), while netting accessible cash and highly liquid short-term investments.
*   **Reported Financial Debt:** Short-term Borrowings (€4,446m) + Current Portion of Long-term Borrowings (€3,097m) + Long-term Borrowings (€19,374m) = €26,917 million.
*   **Lease Liabilities:** Current Lease Liabilities (€884m) + Noncurrent Lease Liabilities (€4,067m) = €4,951 million.
*   **Pension Obligations:** Noncurrent Provisions For Employee Benefits = €786 million.
*   **Asset Retirement Obligations (ARO):** Other Longterm Provisions (principally decommissioning provisions for an O&G company) = €15,267 million.
*   **Gross Adjusted Debt** = €26,917m + €4,951m + €786m + €15,267m = €47,921 million.
*   **Accessible Cash:** Cash and Cash Equivalents (€10,155m) + Current Financial Assets At Fair Value Through Profit Or Loss (highly liquid short-term marketable securities) (€8,251m) = €18,406 million. (Note: "Other" current financial assets are typically excluded by S&P as they are not reliably accessible/liquid).
*   **S&P Adjusted Net Debt** = €47,921m - €18,406m = **€29,515 million**.

**3. Ratio Calculation**
FFO / S&P Net Debt = €18,739m / €29,515m ≈ 0.6349 (or 63.5%)

<answer>0.63</answer>