For what it worth - in the span of 1998-2000 I was participating in national programming competitions between high school students in Belarus. On a day of actua

For what it worth - in the span of 1998-2000 I was participating in national programming competitions between high school students in Belarus. On a day of actual event every participants were given bar of chocolate. Can't say if it helped my cognitive function or not, but it was nice to have chocolate snack before working on solving problems :)