(Solved): A 3-character string, userCode, is read from input. Replace the first and second characters in use ...

A 3-character string, userCode, is read from input. Replace the first and second characters in userCode with ' $${}^{?}$$ ' only if both are digit characters. Otherwise, userCode is not changed. Ex: If the input is 268 , then the output is: $$??8$$ Ex: If the input is $$4\mathrm{j}h$$, then the output is: $$4\mathrm{jh}$$