The undirected graph without loops and multiple edges is given. Remove the minimum number of edges to make a graph disconnected. \InputFile Two numbers \textbf{n} and \textbf{k} (\textbf{2} ≤ \textbf{n} ≤ \textbf{100}, \textbf{0} ≤ \textbf{k} ≤ \textbf{n·(n-1)/2}) - the number of vertices and edges in a graph. Then given \textbf{k} lines, each contains two numbers - \textbf{a} and \textbf{b} (\textbf{1} ≤ \textbf{a}, \textbf{b} ≤ \textbf{n}) - the numbers of the vertices, connected with an edge. \OutputFile One number - the minimum number of edges to make a graph disconnected.