import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.*;

public class Test {
    public static void main(String args[]) throws IOException {
        new Test(new Scanner(System.in));
    }

    Graph g;
    // functions as defined above
    int []dp1, dp2;
    int []C;

    // pV is parent of node V
    void dfs(int V, int pV) {
        // for storing sums of dp1 and max(dp1, dp2) for all children of V
        int sum1=0, sum2=0;

        // traverse over all children
        for(Edge v : g.adj[V]) {
            if(v.j == pV) continue;
            dfs(v.j, V);
            sum1 += dp2[v.j];
            sum2 += Math.max(dp1[v.j], dp2[v.j]);
        }

        dp1[V] = C[V] + sum1;
        dp2[V] = sum2;
    }

    Test(Scanner in) throws IOException {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        dp1 = new int[50];
        dp2 = new int[50];
        g = new Graph(in.nextInt()+1);
        int M = in.nextInt();
        C = new int[] { 1, 0, 0, 22, 22, 0, 0 };

        while(M-->0)
        {
            int i = in.nextInt();
            int j = in.nextInt();
            g.add(i, j);
        }

        dfs(1, 0);
        int ans = Math.max(dp1[1], dp2[1]);

        System.out.println(ans);
    }

    class Graph
    {
        int N, M;

        ArrayList<Edge>[] adj;

        Graph(int NN)
        {
            M = 0;
            adj = new ArrayList[N=NN];
            for(int i=0; i<N; i++)
                adj[i] = new ArrayList<>();
        }

        void add(int i, int j)
        {
            adj[i].add(new Edge(j, M));
            adj[j].add(new Edge(i, M));
            M++;
        }
    }

    class Edge
    {
        int j, id;

        Edge(int jj, int ii) {
            j=jj; id=ii;
        }
    }
}