There is integer number $\displaystyle m\geqslant 2$. Find the smallest integer number $\displaystyle n\geqslant m$, such that for every division of set $\displaystyle \lbrace m, m+1, ..., n\rbrace$ into two subsets at least one of thease subsets contains such numbers $\displaystyle a, b, c$ (not necessarily different), such that $\displaystyle ab=c$.