Here comes the next batch of our 72 #CAcert mini tasks. Choose your favourite. Can you manage to solve one by summer?

https://bugs.cacert.org/view.php?id=1544
https://bugs.cacert.org/view.php?id=1473
https://bugs.cacert.org/view.php?id=1440
https://bugs.cacert.org/view.php?id=1343