For the integer $n(n \geqslant 4)$, find the smallest integer $f(n)$, such that for any positive integer $m$, any $f(n)$-element subset of the set $\{m, m+1, \cdots, m+n-1\}$ contains at least 3 pairwise coprime elements.
When $n \geqslant 4$, for the set $M=\{m, m+1, m+2, \cdots, m+n-1\}$, if $2 \mid m$, then $m+1, m+2, m+3$ are pairwise coprime; if $2 \nmid m$, then $m, m+1, m+2$ are pairwise coprime.

Thus, in all $n$-element subsets of $M$, there are at least 3 elements that are pairwise coprime. Therefore, $f(n)$ exists, and $f(n) \leqslant n$.