The directed graph is given. Determine, does it contain a cycle. \InputFile First line contains number of vertices $n~(n \le 50)$. Each of the next $n$ lines contains $n$ numbers, each of them is either $0$ or $1$. $j$-th number in the $i$-th line equals to $1$ if and only if there exist an edge from $i$-th vertex to $j$-th. It is guaranteed that diagonal of the matrix contains zeros. \OutputFile Print $0$ if there is no cycle in the graph and $1$ if cycle exists. \includegraphics{https://static.e-olymp.com/content/f9/f97f562d45d29cb7850454b2966467f12e29bc92.gif}