aia_iai 满足
{a2+a3+⋯+an≤s1a1+a3+⋯+an≤s2a1+a2+⋯+an≤s3⋮a1+a2+⋯+an−1≤sna1≤m1a2≤m2a3≤m3⋮an≤mn\begin{cases} a_2+a_3+\dots+a_n\le s_1\\ a_1+a_3+\dots+a_n\le s_2\\ a_1+a_2+\dots+a_n\le s_3\\ \vdots\\ a_1+a_2+\dots+a_{n-1}\le s_n\\ a_1\le m_1\\ a_2\le m_2\\ a_3\le m_3\\ \vdots\\ a_n\le m_n \end{cases}⎩⎨⎧a2+a3+⋯+an≤s1a1+a3+⋯+an≤s2a1+a2+⋯+an≤s3⋮a1+a2+⋯+an−1≤sna1≤m1a2≤m2a3≤m3⋮an≤mn
ai∈Na_i\in \mathbb{N}ai∈N
求 ∑ai\sum a_i∑ai 的最大值
