problems with reading a graph

hi

I cannot have cluto read even the simplest graph.
I run scluster with the following graph (4 vertices, 6 edges)

4 6
2 1.5 3 0.1 4 0.2
3 0.5 4 0.1
4 2.8

The message I get is:

Similarity value could not be found for edge (1 0)

Aborted