The formula mentioned for creating batches of 100 contacts

=ifs(row(D2)<100,"dr1",row(D2)<200,"dr2",row(D2)<300,"dr3",row(D2)<400,"dr4",row(D2)<500,"dr5",row(D2)<600,"dr6",row(D2)<700,"dr7",row(D2)<800,"dr8",row(D2)<900,"dr9",row(D2)<1000,"dr10",row(D2)<1100,"dr11",row(D2)<1200,"dr12",row(D2)<1300,"dr13",row(D2)<1400,"dr14",row(D2)<1500,"dr15",row(D2)<1600,"dr16",row(D2)<1700,"dr17",row(D2)<1800,"dr18",row(D2)<1900,"dr19",row(D2)<2000,"dr20",row(D2)<2100,"dr21",row(D2)<2200,"dr22",row(D2)<2300,"dr23",row(D2)<2400,"dr24",row(D2)<2500,"dr25",row(D2)<2600,"dr26",row(D2)<2700,"dr27",row(D2)<2900,"dr28",row(D2)<3000,"dr29",row(D2)<3100,"dr30",row(D2)<3200,"dr31",row(D2)<3300,"dr32",row(D2)<3300,"dr33",row(D2)<3400,"dr34",row(D2)<3500,"dr35",row(D2)<3600,"dr36",row(D2)<3700,"dr37",row(D2)<3800,"dr38",row(D2)<3900,"dr39",row(D2)<4000,"dr40",row(D2)<4100,"dr41",row(D2)<4200,"dr42",row(D2)<4300,"dr43",row(D2)<4400,"dr44",row(D2)<4500,"dr45",row(D2)<4600,"dr46",row(D2)<4700,"dr47",row(D2)<4800,"dr48",row(D2)<4900,"dr49",row(D2)<5000,"dr50",row(D2)<5100,"dr51",row(D2)<5200,"dr52",row(D2)<5300,"dr53",row(D2)<5400,"dr54",row(D2)<5500,"dr55",row(D2)<5600,"dr56",row(D2)<5700,"dr57",row(D2)<5800,"dr58",row(D2)<5900,"dr59",row(D2)<6000,"dr60",row(D2)<6100,"dr61",row(D2)<6200,"dr62",row(D2)<6300,"dr63",row(D2)<6400,"dr64",row(D2)<6500,"dr65",row(D2)<6600,"dr66",row(D2)<6700,"dr67",row(D2)<6800,"dr68",row(D2)<6900,"dr69",row(D2)<7000,"dr70",row(D2)<7100,"dr71",row(D2)<7200,"d72",row(D2)<7300,"dr73",row(D2)<7400,"dr74",row(D2)<7500,"dr75",row(D2)<7600,"dr76",row(D2)<7700,"dr77",row(D2)<7800,"dr78",row(D2)<7900,"dr79",row(D2)<8000,"dr80",row(D2)<8100,"dr81",row(D2)<8200,"dr82")