flow.size: 8
row.1: 0,0,0,0,0,0,0,8
row.2: 0,0,0,0,2,0,1,0
row.3: 0,0,4,0,8,0,5,0
row.4: 2,6,0,0,0,0,0,0
row.5: 0,7,0,0,0,0,0,0
row.6: 0,0,0,0,4,6,0,1
row.7: 0,3,7,0,5,0,0,3
row.8: 0,0,0,0,0,0,0,0












