(a) Prove that for every positive integer mm there exists an integer nmn \geq m such that

n1n2nm=(nm).(*)\left\lfloor \frac {n}{1} \right\rfloor \cdot \left\lfloor \frac {n}{2} \right\rfloor \cdots \left\lfloor \frac {n}{m} \right\rfloor = \binom {n} {m}. \tag{*}

(b) Denote by p(m)p(m) the smallest integer nmn \geq m such that the equation (*) holds. Prove that p(2018)=p(2019)p(2018) = p(2019).

Remark: For a real number xx, we denote by x\lfloor x \rfloor the largest integer not larger than xx.