What is the Total Value Realized on Exercise?
{"Mark J. Barrenechea": {"Number of Shares Acquired on Exercise (#)": 135208, "Value Realized on Exercise(1) ($)": 2801023, "Number of Shares Acquired on Vesting (#)": 65820, "Value Realized on Vesting(2) ($)": 7625905}, "Madhu Ranganathan": {"Number of Shares Acquired on Exercise (#)": "\u2014", "Value Realized on Exercise(1) ($)": "$\u2014", "Number of Shares Acquired on Vesting (#)": "\u2014", "Value Realized on Vesting(2) ($)": "$\u2014"}, "Muhi Majzoub": {"Number of Shares Acquired on Exercise (#)": 100000, "Value Realized on Exercise(1) ($)": 2592411, "Number of Shares Acquired on Vesting (#)": 10900, "Value Realized on Vesting(2) ($)": 1263646}, "Gordon A. Davies": {"Number of Shares Acquired on Exercise (#)": "\u2014", "Value Realized on Exercise(1) ($)": "$\u2014", "Number of Shares Acquired on Vesting (#)": 12840, "Value Realized on Vesting(2) ($)": 1486870}, "Simon Harrison": {"Number of Shares Acquired on Exercise (#)": 26504, "Value Realized on Exercise(1) ($)": 714495, "Number of Shares Acquired on Vesting (#)": 8980, "Value Realized on Vesting(2) ($)": 346808}}
total_value = df["Mark J. Barrenechea"]["Value Realized on Exercise(1) ($)"] + df["Muhi Majzoub"]["Value Realized on Exercise(1) ($)"] + df["Simon Harrison"]["Value Realized on Exercise(1) ($)"]
answer = total_value