Maximum Clique

Given a graph $G(V,E)$, a clique is a sub-graph $g(v,e)$, so that for all vertex pairs $v_1$, $v_2$ in $v$, there exists an edge ($v_1$, $v_2$) in $e$. Maximum clique is the clique that has maximum number of vertex.

Input

Consists of multiple tests. The first line of each test case contains the number of vertices $n$ $(1<n\le 50)$. The following $n$ lines has $n$ numbers $0$ or $1$ each, indicating whether an edge exists between $i$ (line number) and $j$ (column number). The last line contains $n$ = $0$ and must not be processed.

Output

For each test case print on a separate line the number of vertices in maximum clique.

Examples