No. Let me explain. When I directly use String for grouping, each file is under its own group. Earlier, all files starting with say 10 were under one group, now each file under 10(10.0001, 10.0002, 10.0003,...) is divided into its own group. 10.0001 is under 10.0001 group and 10.0002 under 10.0002 and so on.