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












