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












