using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Linq;
using System.Runtime.InteropServices.ComTypes;


class Program
{
    static void Main(string[] args)
    {
        var inp = arrInt();
        int n = inp[0];
        int m = inp[1];
        var fMap = mapInt(m);
        UnionFind uni = new UnionFind(n);
        foreach (var p in fMap) uni.unite(p[0]-1, p[1]-1);
        int max = 0;
        for (int i = 0; i < n; i++) max = Math.Max(max, uni.size(i));
        Console.WriteLine(max);        
    }




    //入力受け取り用
    static string crS() { return Console.ReadLine(); }
    static int crI() { return int.Parse(Console.ReadLine()); }
    static int[] arrInt() { return Console.ReadLine().Split(' ').Select(v => int.Parse(v)).ToArray(); }
    static long[] arrLong() { return Console.ReadLine().Split(' ').Select(v => long.Parse(v)).ToArray(); }
    static string[] arrStr() { return Console.ReadLine().Split(' ').ToArray(); }
    static List<int[]> mapInt(int h)
    {
        List<int[]> mapInt = new List<int[]>();
        for (int i = 0; i < h; i++)
        {
            mapInt.Add(arrInt());
        }
        return mapInt;
    }

    static List<string[]> mapStr(int h)
    {
        List<string[]> mapStr = new List<string[]>();
        for (int i = 0; i < h; i++)
        {
            mapStr.Add(arrStr());
        }
        return mapStr;
    }

    static List<char[]> mapChar(int h)
    {
        List<char[]> mapChar = new List<char[]>();
        for (int i = 0; i < h; i++)
        {
            string s = crS();
            mapChar.Add(s.ToCharArray());
        }
        return mapChar;
    }

    static List<char[]> mapCharCopy(List<char[]> map)
    {
        List<char[]> copyMap = new List<char[]>();
        foreach (var arr in map)
        {
            List<char> list = new List<char>();
            foreach (var ele in arr)
            {
                list.Add(ele);
            }
            copyMap.Add(list.ToArray());
        }
        return copyMap;
    }
}

  class UnionFind
    {
        int n;
        int[] par;
        int[] rank;
        int[] sizeArr;

        public UnionFind(int n)
        {
            this.n = n;

            par = new int[n];
            rank = new int[n];
            sizeArr = new int[n];

            //n要素で初期化
            for(int i = 0; i < n; i++)
            {
                par[i] = i;
                rank[i] = 0;
                sizeArr[i] = 1;
            }
        }

        //木の根を求める
        public int find(int x)
        {
            if(par[x] == x)
            {
                return x;
            } else
            {
                return par[x] = find(par[x]);
            }
        }

        //xとyの属する集合を併合
        public void unite(int x, int y)
        {
            x = find(x);
            y = find(y);
            if (x == y) return;
            if(rank[x] < rank[y])
            {
                par[x] = y;
            }
            else
            {
                par[y] = x;
                if (rank[x] == rank[y]) rank[x]++;
            }
            int tmp = sizeArr[x];
            sizeArr[x] += sizeArr[y];
            sizeArr[y] += tmp;
        }

        //xとyが同じ集合に属するか否か
        public bool same(int x,int y)
        {
            return find(x) == find(y);
        }

        public int size(int x)
        {
            return sizeArr[x];
        }

    }



Measured memory_bytes: 54492