What is the change in Cash and cash equivalents between 2018 and 2019?
{"Short-term borrowings -- Bonds": {"2019 m": -53, "Restated1 2018 m": -3477}, "Short-term borrowings -- Commercial paper": {"2019 m": -873, "Restated1 2018 m": -2712}, "Short-term borrowings -- Bank loans": {"2019 m": -1220, "Restated1 2018 m": -1159}, "Short-term borrowings -- Other short-term borrowings2": {"2019 m": -2124, "Restated1 2018 m": -1165}, "Short-term borrowings -- ": {"2019 m": -4270, "Restated1 2018 m": -8513}, "Long-term borrowings -- Bonds": {"2019 m": -44439, "Restated1 2018 m": -30473}, "Long-term borrowings -- Bank loans": {"2019 m": -1780, "Restated1 2018 m": -2157}, "Long-term borrowings -- Other long-term borrowings3": {"2019 m": -2466, "Restated1 2018 m": -278}, "Long-term borrowings -- ": {"2019 m": -48685, "Restated1 2018 m": -32908}, "Long-term borrowings -- Cash and cash equivalents": {"2019 m": 13637, "Restated1 2018 m": 4674}, "Other financial instruments -- Derivative financial instruments included in trade and other receivables (note 14)": {"2019 m": 3634, "Restated1 2018 m": 2629}, "Other financial instruments -- Derivative financial instruments included in trade and other payables (note 15)": {"2019 m": -2444, "Restated1 2018 m": -2383}, "Other financial instruments -- Short-term investments (note 13)": {"2019 m": 11095, "Restated1 2018 m": 6870}, "Other financial instruments -- ": {"2019 m": 12285, "Restated1 2018 m": 7116}, "Other financial instruments -- Net debt": {"2019 m": -27033, "Restated1 2018 m": -29631}}
cash_2019 = df["Long-term borrowings -- Cash and cash equivalents"]["2019 m"]
cash_2018 = df["Long-term borrowings -- Cash and cash equivalents"]["Restated1 2018 m"]
answer = cash_2019 - cash_2018