**Step 1: Identify the Relevant Industry**

From the narrative facts, HERA S.P.A. is a multi-utility company based in Italy, operating in the distribution of gas, water, electricity, and waste management services. Given the "Multi-utilities" subsector listed under "Regulated Utilities" and the presence of typical regulated utility financial line items (e.g., "Right-of-use Assets", "Noncurrent Provisions for Employee Benefits"), the relevant industry is **Regulated Utilities**.

**Step 2: Estimate Adjusted Debt**

Baseline formula: `Adjusted_Debt = (reported_debt + leases + pension_deficit + guarantees + hybrid_debt_portion + other_debt_like_items) - eligible_cash`

Let's identify the components from the 2022 balance sheet (as of 2023-01-01):

1.  **Reported Debt:** This is typically the sum of Noncurrent and Current Financial Liabilities.
    - Noncurrent Financial Liabilities: 5,689,900,000 EUR
    - Current Financial Liabilities: 650,100,000 EUR
    - Reported Debt = 5,689,900,000 + 650,100,000 = 6,340,000,000 EUR

2.  **Leases:** Right-of-use assets correspond to lease liabilities.
    - Noncurrent Lease Liabilities: 55,100,000 EUR
    - Current Lease Liabilities: 21,300,000 EUR
    - Leases = 55,100,000 + 21,300,000 = 76,400,000 EUR

3.  **Pension Deficit:** S&P typically adds the unfunded portion of defined benefit obligations. We look at "Noncurrent Provisions for Employee Benefits".
    - Noncurrent Provisions for Employee Benefits: 92,000,000 EUR
    - *(Note: Sometimes a portion is funded via plan assets, but in the absence of a surplus figure that can be netted, the gross provision is treated as deficit).*

4.  **Guarantees, Hybrid Debt, Other Debt-like Items:** No information is provided suggesting material amounts for these specific line items beyond what's captured. We'll assume none.

5.  **Eligible Cash:** S&P typically allows companies to deduct surplus cash. However, for utilities, especially in Europe, cash is often considered necessary for operations and is not deducted, or only deducted partially. Without specific data on trapped cash or minimum operating requirements, a conservative baseline approach is to assume no cash deduction if it's not explicitly stated as surplus. However, standard S&P practice allows deduction of cash and cash equivalents if considered surplus.
    - Cash and Cash Equivalents: 1,942,400,000 EUR.
    - Given the magnitude, assuming *no* surplus cash deduction could be overly punitive. We will present the unadjusted figure, and then a standard adjustment. Often, S&P deducts only a portion. In the absence of specific guidance on minimum cash, we will calculate without cash deduction for a strict view, but the prompt asks for the S&P methodology estimate. S&P typically deducts "surplus" cash. We'll assume standard treatment without a specific disclosed surplus amount is to deduct available cash. Let's follow the baseline formula as given: "eligible_cash". Often, this is all cash unless specified otherwise. We'll proceed with deducting all cash.
    - *Self-correction*: The baseline formula doesn't specify a floor for cash. We'll assume cash and cash equivalents are eligible.

**Adjusted Debt Calculation:**
Adjusted_Debt = 6,340,000,000 (Debt) + 76,400,000 (Leases) + 92,000,000 (Pension) - 1,942,400,000 (Cash)
Adjusted_Debt = 6,508,400,000 - 1,942,400,000 = 4,566,000,000 EUR

**Step 3: Estimate Adjusted EBITDA**

Baseline formula: `Adjusted_EBITDA = EBITDA + adjustment_leases + nonrecurring_losses - nonrecurring_gains ± pension_adjustments ± joint_venture_proportional_EBITDA ± other_normalization_adjustments`

First, let's reconstruct EBITDA from the income statement for the fiscal year ended 2022-12-31 (period 2022-01-01 to 2023-01-01).

- Operating Profit (EBIT): 533,800,000 EUR
- Amortisation, Depreciation and Provisions: 667,100,000 EUR
- EBITDA (Operating Profit + Depreciation): 533,800,000 + 667,100,000 = 1,200,900,000 EUR

Now, let's analyze the adjustments required by the Regulated Utilities methodology and baseline formula:

1.  **Leases:** S&P usually adds back lease depreciation and interest to calculate EBITDAR, but the baseline formula says `EBITDA + adjustment_leases`. The standard S&P adjustment is to add back operating lease expenses (which for IFRS 16 are already capitalized, so the right-of-use asset depreciation and interest are added back, effectively converting EBIT to EBITDAR). Since EBITDA already adds back depreciation, the main lease adjustment is adding back the interest portion of lease payments.
    - Finance Costs for leases are not separated out in the standard income statement provided. We'll assume the `Finance Costs` include lease interest. Since we don't have the split, we can't adjust this precisely. Often, debt/EBITDA includes leases in the debt, but the EBITDA is just standard EBITDA. The prompt baseline says "EBITDA (reported or reconstructed) + adjustment_leases (if any)". Given limited data, we will use the reconstructed EBITDA and note that no explicit lease adjustment is made on the EBITDA side (common practice for IFRS 16 where depreciation is already added back, and lease interest is small). Let's assume no adjustment for simplicity, or add back the full lease expense if known.
    - *Alternative common S&P practice:* Add back lease expense (Depreciation from Right-of-use + Interest on lease). We don't have the split. We will not double-add back the depreciation, as it's already in D&A. The interest portion is included in finance costs. To be precise, S&P adds back the implied lease interest. We lack the data to do this. We'll proceed with the EBITDA as is.

2.  **Non-recurring items:** No specific non-recurring losses or gains are detailed in the provided facts.

3.  **Pension adjustments:** S&P adjusts EBITDA by adding back the service cost component of defined benefit plans and subtracting the actual benefits paid (or vice versa, to reflect the operating cost rather than just the accounting charge). In the absence of a detailed breakdown, we can approximate by looking at the "Allocation To Provisions" and changes in "Provisions For Employee Benefits".
    - Allocation to Provisions (excluding risk and charges): 188,500,000 EUR
    - Adjustments for Increase/Decrease in Employee Benefit Liabilities: -12,700,000 EUR
    - Let's assume the total employee benefit charge in EBITDA is the "Employee Benefits Expense": 601,100,000 EUR. S&P typically uses the operating cost. Without the detailed breakdown of service vs. interest cost, we will assume no adjustment is made to the standard EBITDA figure, as the non-service cost portions are typically small in many European contexts or we lack the precise numbers.

4.  **Joint ventures:** Share of Profit/Loss of Associates: 10,000,000 EUR. This is usually post-tax and post-interest, but S&P sometimes adjusts EBITDA proportionally. We will omit this adjustment due to missing data on proportionally consolidated debt.

**Adjusted EBITDA:**
Adjusted_EBITDA = 1,200,900,000 EUR

**Step 4: Calculate Adjusted_Debt / Adjusted_EBITDA**

Ratio = 4,566,000,000 / 1,200,900,000 = 3.802...

Rounding to two decimal places: 3.80

<answer>3.80</answer>