7<<<<<<<6
6_7.....8_9.....10_11.....12_13.....14_15.....16_17.....18_19.....20_21.....22_23.....24_25.....26_27.....28_29.....
30_31.....32_33.....34_35.....36_37.....38_39.....40_41.....42_43
