At the recent jam making contest, four lucky candidates took part

to make the juiciest strawberry jam. The ages of the contestants

were 14, 17, 20 and 22. As it happens the person who came last

was the oldest, whereas Stuart was three years older than the

person who came second. James was neither the oldest nor

the youngest and Kevin finished ahead of the 17 year old, but

didn't win. John was also unlucky this time and didn't win either.

Can you determine who finished where and how old they are?