84=42-+1=41+43
.........-+5=37+47
..........-+11=31+53
...........-+19=23+61
..............25=17+67
...........-+29=13+71
...........-+31=11+73
...........-+37=5+79
d84=8
.........-+5=37+47
..........-+11=31+53
...........-+19=23+61
..............25=17+67
...........-+29=13+71
...........-+31=11+73
...........-+37=5+79
d84=8










