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

