------------------- The default, fixed input format can be replaced by a free format using option FREE or better GLOBAL. The latter allows to choose free format for both the normal input and the geometry input separately, and serves also a few other purposes: it can be used to increase the maximum allowed number of geometry regions, and to force a calculation to be fully analogue (i.e., simulating physical reality as directly as possible, without any biasing to accelerate statistical convergence. A more esoteric capability of GLOBAL, used mainly for debugging, is to ensure that the random number sequence be exactly reproduced even in cases where the geometry tracking algorithm has the possibility to follow different logical paths to achieve the same result.