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











