Microsoft has spent the day doing its best to stump 1,400 college students around the country. The company is holding its fifth annual College Puzzle Challenge, a competition for computer engineering, computer science and math students at 18 universities. Working in teams of four, they've been trying to solve a series of puzzles since 9 a.m. Pacific time.

The puzzle pictured here is one of three Microsoft gave the students in advance, to get them started. The clue is a memo in which a fictional company tells its employees that its board "has identified the following companies that could lead to strategic mergers."  The clue continues, "Please evaluate them and help determine which order we should go after these companies.  After finding the appropriate order, we’ll read down the list and see if anything stands out."

Can you solve it? The answer is a single word. If you think you've figured it out, post your solution in the comments below.

[Update: I won't give away the answer, for anyone still working to solve it, but suffice it to say that you guys know what you're doing, based on some of the comments. If you've cracked this one, here's another.]

[Update II: Here are the solutions to this and the second puzzle.]

Microsoft, which competes against Google and others for top computer-science talent, uses the event to supplement its traditional college recruiting efforts. Teams compete for gift certificates and Xbox products, but winning isn't easy. When I stopped by the University of Washington today, some of the students were impressed with how challenging the puzzles were.

"We did get one in the first 15 minutes, but it's been pretty slow going since then," said Brent Couvrette, 20, a UW computer science major from Woodinville. The students submit their answers via computer as they proceed, so they know when they get one right.

Other participating schools include Carnegie Mellon, MIT and Stanford. The competition goes on for 12 straight hours, ending at 9 tonight Pacific time, and midnight on the East Coast.

[Clockwise from upper left] UW  computer science students Brent Couvrette, Yuki Liang, Steven Kwan and Emma Lynch participate in Microsoft's College Puzzle Challenge today.