S | S1 | S2 | S3 | S4 |
S1 | 1 | 5 | 3 | 7 |
S2 | 1/5 | 1 | 1/3 | 3 |
S3 | 1/3 | 3 | 1 | 5 |
S4 | 1/7 | 1/3 | 1/5 | 1 |