How do you compute the Fundamental group of the 1-skeleton of the 3-cube = ? What about the Fundamental group of the 1- skeleton of the 4-cube ?

I know the Fundamental group of a space X at a point is the set of homotopy classes of loops of X based at . And that the 1-skeleton of a space X is the union of all cells of the CW complex for X up to dimension 1. But how do you find the fundamental group of the 1 skeleton for those cubes?