java weka.clusterers.MPCKMeans \
	-D data/iris.arff \
	-C data/iris.constraints \
	-N 3 \
	-O iris.assignments \
	-K 1

Notes: 

1. Be careful about the -K option, because for some arff files the class 
attribute is at the front, while for the others it is at the end.  If -K 
is not specified, MPC-KMeans assumes that the *last* attribute is the 
class variable.

2. Add -V option if *no* transitive closure of constraints is desired.