Easy# Composition of Loops

TOPO-BJQYYD

What is the winding number (i.e. the corresponding element of the fundamental group $\pi_1(\mathbb R^2-\{(0,0)\})=\mathbb Z$) with respect to the origin of the composition of two loops, one of winding number $7$ with respect to the origin and one of winding number $-3$ with respect to the origin?