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