As per my view it may be
Coach position from engine of S4=11
Eng-SLR-GS-GS-GS-A1-B1-B2-S1-S2-S3-S4-S5-S6-GS-GS-GS-SLR=17 COACHES
OR
Coach position from engine of S4=7
Eng-SLR-GS-GS-GS-S6-S5-S4-S3-S2-S1-B2-B1-A1-GS-GS-GS-SLR=17...
more... COACHES
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Please do write the coach composition if possible so that same may be updated here. Thanks