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












