Automatically pop up a number in column B depending on the text from column A

[Elainefish]

I want to: Automatically pop up a number in column B depending on the text from column A

for example
Los Angeles = 1
New York = 2
Colorado = 3


So, If I chose "Los Angeles in column A, B will automatically populate 1

here is my sample sheet calculation_question3.xlsx

[Fotis1991]

Unmerged cells from D16:D27 and try this in D5

=IFERROR(INDEX($D$16:$D$28;MATCH(B5;$B$16:$B$28;0));"")

=IFERROR(INDEX($D$16:$D$28,MATCH(B5,$B$16:$B$28,0)),"")