How do i make input correct to be both lower and uppercase?

I need to find out how to make this if statment to accept the imput as capital or lower case c.

Could someone please help me out with it ?

x = input('Answer is c or C','s');
if x ~= lower('C') ,or upper('c')
    disp('incorrect')
elseif x == lower('C') ,or upper('c')
    disp('correct')
end

Answer 1

[Ameer Hamza]

Apply lower() on the input x

x = input('Answer is c or C','s');
if lower(x) ~= 'c'
    disp('incorrect')
elseif lower(x) == 'c'
    disp('correct')
end