64. Fill in the $\square$ with digits to make the equation true.
$$
\begin{array}{r}
\square 2 \square 6 \\
-\quad \square 97 \\
\hline 543 \square
\end{array}
$$
$$
\begin{array}{r}
6236 \\
-\quad 797 \\
\hline 5439
\end{array}
$$