1. Let $n!=1 \times 2 \times 3 \times \cdots \times n, a^{n}=\underbrace{a \times a \times \cdots \times a}_{n \uparrow a}$. If $m$ is a natural number, and $12^{m}$ is a factor of 100!, then the maximum value of $m$ is . $\qquad$
$48$