by@kurgm
AC
531ms
@z=glob`dd`;$A+=(@z[$_][email protected][$_+3])*($_>[email protected][++$_%3+3]*@z[$t=($_+1)%3][email protected][$_%3]*@z[$t+3]:0)for 0..8;print$A/6
17 95 05 26 25 62 68 04 67 77 15 97
19332
0+1 records in 0+1 records out