formula for looking at a text string for a letter

I am needing a formula to look at another cell and if the last character in the cell is a letter, return one value, and if the last character is a number, return another value

Example Cell B1 would look at A1 and if the last character in A1 is a letter is would give the result of "Yes", if the last character is a number it would give the result of "No"

A B
1 4391-1B Yes
2 4391-2 No
3 4390-2C Yes

thanks, worked like a charm