Acceleration unit (HP50)

[CMarangon]

Hello!

I am making a program to calculate
S = So + Vo.t + a.t²/2

Program asks:

Enter values for So Vo t a.
Replace numbers and keep units

100_m 200_m/s 3_s 5m/s^2

Press [ENTER] and it returns value in meters.
S: 722.5_m

Question is:
is there a way to write acceleration unit as m/s² instead of m/s^2?

When I write m/s² it does not work.