size 5
1-: r1c1, r1c2
3/: r1c5, r1c4
2-: r5c3, r4c3
1-: r4c1, r3c1
1-: r3c3, r2c3
5: r2c1
8x: r5c2, r5c1, r4c2
5+: r2c4, r3c4
2-: r3c2, r2c2
4/: r2c5, r3c5
20x: r5c4, r4c4
2: r1c3
2: r5c5
5: r4c5
