#include <bits/stdc++.h>

inline long long read(){long long x=,f=;char ch=getchar();while(ch<''||ch>''){if(ch=='-')f=-;ch=getchar();}while(ch>=''&&ch<=''){x=x*+ch-'';ch=getchar();}return x*f;}

using namespace std;

#define ls i<<1

#define rs ls | 1

#define mid ((ll+rr)>>1)

#define MP make_pair

typedef long long LL;

typedef unsigned long long ULL;

const long long INF = 1e18+1LL;

const double pi = acos(-1.0);

const int N = 2e5 + , M = , inf = 1e9;

vector<int > G[N];

int dp[N][],n,m,fa[N];

int dep[N];

void gao(int x,int y) {

    //cout<<x<<" " <<y<<endl;

    int last0 = , last1 = ;

    for(int i = x; i != y; i = fa[i]) {

        int tmp = last0;

        last0 = max(last0,last1) + dp[i][];

        last1 = tmp + dp[i][];

    }

    dp[y][] += max(last1,last0);

   // int fuck =  max(last0,last1);

    last0 = -inf, last1 = ;

    for(int i = x; i != y; i = fa[i]) {

        int tmp = last0;

        last0 = max(last0,last1) + dp[i][];

        last1 = tmp + dp[i][];

    }

   // fuck = max(max(last0,last1),fuck);

    //dp[y][0] += fuck;

    dp[y][] += last0;

}

void dfs(int u,int f) {

    dep[u] = dep[f] + ;

    fa[u] = f;

    dp[u][] = ;

  //  cout<<u<<" "<<f<<endl;

    for(int i = ; i < G[u].size(); ++i) {

        int to = G[u][i];

        if(to == f) continue;

        if(!dep[to]) {dfs(to,u);}

    }

    for(int i = ; i < G[u].size(); ++i) {

        int to = G[u][i];

        if(to == f) continue;

        if(dep[to] > dep[u] && fa[to] != u) {///montherfuck

            gao(to,u);

        }

    }

}

int main() {

    scanf("%d%d",&n,&m);

    for(int i = ; i <= m; ++i) {

        int u,v;

        scanf("%d%d",&u,&v);

        G[u].push_back(v);

        G[v].push_back(u);

    }

    dfs(,);

    printf("%d\n",max(dp[][],dp[][]));

    return ;

}

/*

17 20

1 2

2 3

3 4

4 5

5 2

2 6

6 7

7 8

8 9

9 10

10 11

11 12

12 6

6 13

13 14

14 15

15 16

16 17

17 13

13 1

*/