3.5-4.5 \text {3.5-4.5}3.5-4.5
4.5-5.5 \text {4.5-5.5}4.5-5.5
5.5-6.5 \text {5.5-6.5}5.5-6.5
6.5-7.5 \text {6.5-7.5}6.5-7.5
