A millennial problem: Find all the pairs of integers which satisfy the
equation

                        XY = X + Y + 2000


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All midshipmen submitting correct solutions to problem #106 by noon on
Tuesday, January 18, win a cookie. The best solution will be posted on the
problem bulletin board.
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A solution is "correct" if it lists all the solutions and explains why
there are no others. A solution is "best" if it includes the clearest
correct explanation. Submit solutions to Prof. Hanna at mathprob@usna.edu,
or via the mailbox in Chauvenet 301.


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Correct solutions to problem #105 (one billion factorial) came from Midn
1/c Gott, 2/c Heineike, and 1/c Gott. There are 249,999,998 zeros at the
end of 1,000,000,000!




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Problem #104 (autobiographical numbers) was quite popular. 17 midshipmen
earned cookies. Several non-midshipmen also submitted solutions. The only
seven autobiographical numbers are 1210, 2020, 21200, 3211000, 42101000,
521001000, and 6210001000.