Heart in heart in heart

Three hearts inside one another: a small 3 × 3 heart in a 5 × 5 heart, which lies on a classic 7 × 7 heart. The colours swap with each heart, so the middle one has a red left lobe and a white right one, and the innermost has them like the big heart. Seven strips in each half, with straight cuts and arcs along the hearts' lobes; in many places the cuts of the two halves lie on top of each other, so they do not show. The halves differ, so there are two templates. The difficulty is expert; the paper gets narrow in several places, so cut slowly and use strong paper.