which city name has the least number of unique letters?
ada
col : name of place | number of counties | principal county | lower zip code row 1 : abbott | 1 | scott county | 72944 row 2 : abco | 1 | hot spring county |  row 3 : aberdeen | 1 | monroe county | 72134 row 4 : acorn | 1 | polk county | 71953 row 5 : ada | 1 | conway county | 72001 row 6 : adams field | 1 | pulaski county | 72202 row 7 : adona | 1 | perry county | 72001 row 8 : advance | 1 | baxter county |  row 9 : aetna | 1 | craighead county |  row 10 : aggie | 1 | craighead county |  row 11 : agnos | 1 | fulton county | 72513 row 12 : agricultural school | 1 | columbia county |  row 13 : air base | 1 | pulaski county | 72076 row 14 : airport village | 1 | jackson county |  row 15 : alamo | 1 | montgomery county |  row 16 : albert | 1 | montgomery county |  row 17 : albion | 1 | white county | 72143 row 18 : alco | 1 | stone county | 72610 row 19 : alexander | 2 | pulaski county | 72002 row 20 : alexander | 2 | saline county | 72002 row 21 : alf | 1 | montgomery county |  row 22 : alix | 1 | franklin county | 72820 row 23 : allbrook | 1 | howard county | 71851 row 24 : alleene | 1 | little river county | 71820 row 25 : almond | 1 | cleburne county | 72550 row 26 : almyra | 1 | arkansas county | 72003 row 27 : alpena | 2 | boone county | 72611 row 28 : alpha | 1 | yell county |  row 29 : alread | 1 | van buren county | 72031 row 30 : altheimer | 1 | jefferson county | 72004 row 31 : altus | 1 | franklin county | 72821 row 32 : aly | 1 | yell county | 72857 row 33 : amagon | 1 | jackson county | 72005 row 34 : amboy | 1 | pulaski county |  row 35 : ames | 1 | nevada county |  row 36 : amity | 1 | clark county | 71920 row 37 : amy | 1 | ouachita county | 71701 row 38 : andrews | 1 | white county |  row 39 : anthony | 1 | hempstead county | 71801 row 40 : anthonyville | 1 | crittenden county | 72301 row 41 : antioch | 1 | craighead county |  row 42 : antioch | 1 | hot spring county |  row 43 : antioch | 1 | perry county | 72070 row 44 : antioch | 1 | white county | 72012 row 45 : appleby | 1 | washington county |  row 46 : applegate ford | 1 | carroll county |  row 47 : apt | 1 | craighead county | 72403 row 48 : arbaugh | 1 | newton county | 72852 row 49 : arcadia | 1 | hempstead county | 71857 row 50 : ard | 1 | yell county | 72834 row 51 : arkadelphia | 1 | clark county | 71923 row 52 : arkana | 1 | baxter county |  row 53 : arkana | 1 | lafayette county | 71826 row 54 : arkansas a and m college | 1 | drew county |  row 55 : arkansas city | 1 | desha county | 71630 row 56 : arkansas polytechnic college | 1 | pope county |  row 57 : arkansas post national memorial | 1 | arkansas county | 72055 row 58 : arkansas state teachers college | 1 | faulkner county |  row 59 : arkola | 1 | sebastian county | 72945 row 60 : arlberg | 1 | stone county |  row 61 : armorel | 1 | mississippi county | 72310 row 62 : armstrong springs | 1 | white county | 72148 row 63 : artesian | 1 | calhoun county |  row 64 : arthur | 1 | conway county | 72156 row 65 : ashdown | 1 | little river county | 71822 row 66 : asher | 1 | madison county | 72727
which city name has the least number of unique letters?
Name of place Number of counties Principal county Lower zip code
Abbott 1 Scott County 72944
Abco 1 Hot Spring County
Aberdeen 1 Monroe County 72134
Acorn 1 Polk County 71953
Ada 1 Conway County 72001
Adams Field 1 Pulaski County 72202
Adona 1 Perry County 72001
Advance 1 Baxter County
Aetna 1 Craighead County
Aggie 1 Craighead County
Agnos 1 Fulton County 72513
Agricultural School 1 Columbia County
Air Base 1 Pulaski County 72076
Airport Village 1 Jackson County
Alabam 1 Madison County 72740
Alamo 1 Montgomery County
Albert 1 Montgomery County
Albert Pike 1 Garland County 71913
Albion 1 White County 72143
Alco 1 Stone County 72610
Alexander 1 Greene County 72450
Alexander 2 Pulaski County 72002
Alexander 2 Saline County 72002
Alf 1 Montgomery County
Alfrey 1 Monroe County 72021
Algoa 1 Jackson County 72112
Alicia 1 Lawrence County 72410
Alix 1 Franklin County 72820
Allbrook 1 Howard County 71851
Alleene 1 Little River County 71820
Allendale 1 Monroe County
Allene 1 Little River County
Allfriend 1 Newton County 72664
Allis 1 Drew County
Allison 1 Stone County 72511
Allport 1 Lonoke County 72046
Alma 1 Crawford County 72921
Almond 1 Cleburne County 72550
Almyra 1 Arkansas County 72003
Alpena 2 Boone County 72611
Alpena 2 Carroll County 72611
Alpha 1 Yell County
Alpine 1 Clark County 71920
Alread 1 Van Buren County 72031
Altheimer 1 Jefferson County 72004
Alto 1 Poinsett County 72354
Altus 1 Franklin County 72821
Aly 1 Yell County 72857
Amagon 1 Jackson County 72005
Amanca 1 Crittenden County 72376
Amboy 1 Pulaski County
Ames 1 Nevada County
Amity 1 Clark County 71920
Amy 1 Ouachita County 71701
Anderson 1 Scott County
Anderson Tully 1 Poinsett County
Andrews 1 White County
Annieville 1 Lawrence County 72434
Anthony 1 Hempstead County 71801
Anthony Subdivision 1 Crittenden County
Anthonyville 1 Crittenden County 72301
Antioch 1 Craighead County
Antioch 1 Hot Spring County
Antioch 1 Perry County 72070
Antioch 1 White County 72012
Antoine 1 Pike County 71922
Apalco 1 Lafayette County
Apex 1 Sebastian County 72938
Aplin 1 Perry County 72126
Appleby 1 Washington County
Applegate Ford 1 Carroll County
Appleton 1 Pope County 72822
Apt 1 Craighead County 72403
Arbaugh 1 Newton County 72852
Arbor Grove 1 Lawrence County 72433
Arcadia 1 Hempstead County 71857
Ard 1 Yell County 72834
Arden 1 Little River County 71822
Arkadelphia 1 Clark County 71923
Arkalite 1 Lonoke County
Arkana 1 Baxter County
Arkana 1 Lafayette County 71826
Arkansas A and M College 1 Drew County
Arkansas City 1 Desha County 71630
Arkansas Fuel Oil Company Village 1 Columbia County 71753
Arkansas Polytechnic College 1 Pope County
Arkansas Post National Memorial 1 Arkansas County 72055
Arkansas State Teachers College 1 Faulkner County
Arkawana 1 Baxter County
Arkinda 1 Little River County 71836
Arkola 1 Sebastian County 72945
Arlberg 1 Stone County
Armorel 1 Mississippi County 72310
Armstrong 1 Sharp County 72482
Armstrong Springs 1 White County 72148
Arnett 1 Washington County
Artesian 1 Calhoun County
Artex 1 Miller County
Arthur 1 Conway County 72156
Artist Point 1 Crawford County
Ashdown 1 Little River County 71822
Asher 1 Madison County 72727
Asher 1 Pulaski County 72204
Ash Flat 2 Sharp County 72513
Ash Flat 2 Fulton County 72513
Ashton 1 Chicot County 71653
Athelstan 1 Mississippi County 72370
Athens 1 Howard County 71971
Atkins 1 Pope County 72823
Atlanta 1 Columbia County 71740
Attica 1 Randolph County 72455
Atwood 1 Howard County
Aubrey 1 Lee County 72311
Augsburg 1 Pope County 72874
Augusta 1 Woodruff County 72006
Aurelle 1 Union County 71765
Aurora 1 Madison County 72740
Austin 1 Conway County 72027
Austin 1 Lonoke County 72007
Austin Station 1 Lonoke County
Auvergne 1 Jackson County 72112
Avant 1 Garland County
Avery 1 Lincoln County 71639
Avilla 1 Saline County 72002
Avoca 1 Benton County 72711
Avon 1 Sevier County 71832
Azor 1 Nevada County 71835
Ada