Genetic Cross question with Corn Kernels?

In Corn, a series of three independent pairs of genes (A, C, R) affect the production of pigment that leads to the kernel color. If any one of the three pairs is in the homozygous recessive state, then no pigment forms in the kernels. However, if at least one dominant allele for each gene is present, then the pigment can form in the Kernel. Two corn Plants with the following genotypes are crossed: AaccRr X aaCcRr

What fraction of the progeny kernels will be pigmented

I know that you have to do a giant punnet square but I dont know how to do these kinds of crosses. I know this is an annoying question but any help would be GREATLY appreciated