[นกกะเต็นปักหลัก]

4. Let $n\geqslant 3$, $\alpha ,\beta ,\gamma \in (0,1), a_k,b_k,c_k\geqslant 0 (k=1,2,3,\cdot \cdot \cdot ,n)$ satisfy the following inequalities
$$\sum_{k = 1}^{n} {(k+\alpha )a_k\leqslant a},\sum_{k = 1}^{n} {(k+\beta )b_k\leqslant b},\sum_{k = 1}^{n} {(k+\gamma )c_k\leqslant c}.$$
If for any above $a_k,b_k,c_k(k=1,2,3,\cdot \cdot \cdot ,n),$ we have $\sum_{k = 1}^{n}{(k+\lambda )a_kb_kc_k}\leqslant \lambda $, find the minimum value of $\lambda $