Broken Life

You are given two strings $S$ and $A$ of lengths $N$ and $M$ respectively. - String $S$ contains characters from the set $\texttt{\{?, a, b, c, d, e\}}$. - String $A$ contains characters from the set $\texttt{\{a, b, c, d, e\}}$. Let $S'$ denote the string formed by replacing **all** the $\texttt{?}$ in $S$ using the characters from the set $\texttt{\{a, b, c, d, e\}}$. Construct $S'$ such th