__U__sing Excel, the numbers are: 616, 637, 677 and 696. This sums to 2626. So the answer is 626.

/* I know this approach was not what you were looking for, but can't resist using Excel when I have a spreadsheet open. :-) */

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/* I know this approach was not what you were looking for, but can't resist using Excel when I have a spreadsheet open. :-) */

See question on Quora