Alice has an idea for a construction toy made from plastic. Each building block is in the shape of an uppercase letter of the alphabet. No other characters are to be used.
Children will simultaneously learn to build and become familiar with the alphabet.
All is going well until Alice learns of the cost of the machinery needed to make a whole alphabet. She decides to start with just two letters. Over time more letters will be released and there will be the excitement of collecting them.
What two letters should she choose at first and why? The idea is to maximise the play value that be be gained from them by allowing both moving and stable structures.
Unlike a certain well-known system, the letters are 3d with no special holes or sockets to join them. Joins must be made via the shape of the letters themselves.
Here is the alphabet. Some flexibility is allowed in assuming the precise dimensions and which stems will fit into which holes.
Extra kudos will go to anyone who manages to create a 3d picture of interesting structures using only these two letters.
If you wish, you may like to specify the third and further letters to be released with reasons for the sequence in which this is done.