pattern for 3B

i, i+1
[AIV]-[DEKNTVY]-[FL]-[DHLNPST]-[CFIV]-X(8,19)-[FGILMV]-[EFHKLRTY]-[LW]-[EKLQRY]

k
[ADNPS]-[AFGLSW]-[DGHPST]-[IL]-[IKNQRTV]-[FILV]-[HKLPSTY]-[AHNPQS]-[ALV]-[DKQRST]-[ILPRSTY](0,1)-[DEKQS]-[DFN]
k+1
[AEIKNQST]-[ADG]-[EFILST]-[FGY]-[EIKLNQTY]-[CLMV]-[ADEIKMSTV]

PS: [ILPRSTY](0,1)-[DEKQS]-[DFN] in k is in the loop.