\pm 1,\pm 2,\pm 3,\pm 5,\pm 6,\pm 12,\pm 15, \pm 30,\pm\frac 12,\pm\frac 32,\pm\frac{15}2,\pm\frac 14,\pm\frac 34,\pm\frac 54,\pm\frac{15}4.