  Addressing a fundamental problem in programmable matter, we present the first
deterministic algorithm to elect a unique leader in a system of connected
amoebots assuming only that amoebots are initially contracted. Previous
algorithms either used randomization, made various assumptions (shapes with no
holes, or known shared chirality), or elected several co-leaders in some cases.
  Some of the building blocks we introduce in constructing the algorithm are of
interest by themselves, especially the procedure we present for reaching common
chirality among the amoebots. Given the leader election and the chirality
agreement building block, it is known that various tasks in programmable matter
can be performed or improved.
  The main idea of the new algorithm is the usage of the ability of the
amoebots to move, which previous leader election algorithms have not used.
