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2013 AMC 12B Question 15

AMC12 · 2013 AMC 12B

Question 15

The number $2013$ is expressed in the form

$$
2013 = \frac{a_1!\,a_2!\cdots a_m!}{b_1!\,b_2!\cdots b_n!},
$$

where $a_1 \ge a_2 \ge \cdots \ge a_m$ and $b_1 \ge b_2 \ge \cdots \ge b_n$ are positive integers and $a_1 + b_1$ is as small as possible. What is $|a_1 - b_1|\,?$
  1. $1$
  2. $2$
  3. $3$
  4. $4$
  5. $5$