first : 1st
second : 2nd
third : 3rd
fourth : 4th
fifth : 5th
sixth : 6th
seventh : 7th
eighth: 8th
ninth : 9th
tenth : 10th
eleventh : 11th
twelfth : 12th
thirteenth : 13th
fourteenth : 14th
fifteenth : 15th
sixteenth: 16th
seventeenth : 17th
eighteenth : 18th
nineteenth : 19th
twentieth : 20th