Maximum cost of a path (2) P70102

Given a directed and complete graph with n vertices, compute the maximum cost of all the paths with the vertices in increasing order. The given graph is represented by an n × n matrix M, where for every pair (i, j) with i ≠ j, m_ij is the (perhaps negative) cost of the arc from i to j.

For instance, the maximum cost of the first test is 100, because of the path 0 → 1 → 3 → 4, with cost 20 − 10 + 90 = 100.

Input

Input consists of the number of vertices n, followed by the matrix M (n lines, each one with n integer numbers), followed by the initial vertex x. Vertices are numbered from 0 to n−1. You can assume 1 ≤ n ≤ 10³, that the diagonal has only zeros, and that the rest of numbers are between −10⁶ and 10⁶.

Output

Print the maximum cost of all the paths with the vertices in increasing order.