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