=INDEX(B!G:G,MIN(IF((A2=B!A$2:A$100)*(B2=B!B$2:B$100)*(C2=B!C$2:C$100)*(D2=B!D$2:D$100)*(E2=B!E$2:E$100)*(F2=B!F$2:F$100),ROW($2:$100),4^8)))