How can I input variables to dsolve?

I'm writing a function using dsolve, and earlier in the function I request input from the user at the keyboard, and save this input to the variable "A". When using dsolve, I cite the variable "A", but dsolve's solution leaves in the letter A instead of replacing it with the numerical answer the user provides. How can I fix this? Below is my code. I've tried using syms but I'm not sure how to make it work.

A=input('Enter the initial amount of the parent:');

Q=dsolve('DQ=(-1)*L*Q','Q(0)=A','t')

%The output is: Q = A/exp(L*t)

%I want A to take on the value that the user enters at the keyboard (for example, 7). Please help!

Answer 1

[Walter Roberson]

subs(Q, 'A', A)