## Welcome to our monthly puzzles

## You are cordially invited to match wits with some of the best minds in IBM Research.

Seems some of us can't see a problem without wanting to take a crack at solving it. Does that sound like you? Good. Forge ahead and ponder this month's problem. We'll post a new one every month, and allow a month for you to submit solutions (we may even publish submitted answers, especially if they're correct). We usually won't reply individually to submitted solutions but every few days we will update a list of people who answered correctly. At the beginning of the next month, we'll post the answer.

So give your mind a break from its routine---you never know what other problems you may solve in the process!

The current puzzlemaster is Oded Margalit. He took over from James B. Shearer, who took over from the original puzzlemaster Don Coppersmith, in October 2005.

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*If you have any problems you think we might enjoy, please send them in. All replies should be sent to:*
ponder@il.ibm.com

Ponder **This** Top 30 SolversList Updated: 11/06/2019 @ 12:00 PM EST

**Dan Dima**Solved

**133**challenges

**Daniel Bitin**Solved

**126**challenges

**Joseph DeVincentis**Solved

**124**challenges

**Clive Tong**Solved

**90**challenges

**Liubing Yu**Solved

**84**challenges

**David Greer**Solved

**83**challenges

**John G. Fletcher**Solved

**82**challenges

**David Friedman**Solved

**80**challenges

**Radu-Alexandru Todor**Solved

**77**challenges

**Motty Porat**Solved

**76**challenges

**Harald Bögeholz**solved

**76**challenges

**Amos Guler**solved

**75**challenges

**Andreas Stiller**Solved

**72**challenges

**Armin Krauss**Solved

**69**challenges

**Todd Will**Solved

**66**challenges

**Nyles Heise**Solved

**65**challenges

**James Dow Allen**Solved

**64**challenges

**Albert Stadler**Solved

**64**challenges

**Mathias Schenker**Solved

**62**challenges

**John Tromp**Solved

**62**challenges

**Chuck Carroll**Solved

**62**challenges

**Chris Shannon**solved

**61**challenges

**Peter Gerritson**Solved

**61**challenges

**Florian Fischer**solved

**58**challenges

**Shirish Chinchalkar**solved

**57**challenges

**Michael Brand**solved

**56**challenges

**Reiner Martin**solved

**56**challenges

**Stéphane Higueret**solved

**55**challenges

**Tamir Ganor**solved

**55**challenges

**Kang Jin Cho**solved

**52**challenges