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












