  In the 1980's Daryl Cooper introduced the notion of a C-complex (or
clasp-complex) bounded by a link and explained how to compute signatures and
polynomial invariants using a C-complex. Since then this was extended by works
of Cimasoni, Florens, Mellor, Melvin, Conway, Toffoli, Friedl, and others to
compute other link invariants. Informally a C-complex is a union of surfaces
which are allowed to intersect each other in clasps. The purpose of the current
paper is to study the minimal number of clasps amongst all C-complexes bounded
by a fixed link $L$. This measure of complexity is related to the number of
crossing changes needed to reduce $L$ to a boundary link. We prove that if $L$
is a 2-component link with nonzero linking number, then the linking number
determines the minimal number of clasps amongst all C-complexes. In the case of
3-component links, the triple linking number provides an additional lower bound
on the number of clasps in a C-complex.
