import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.util.*;

public class Main {
    static InputStream is;
    static PrintWriter out;
    static String INPUT = "";

    static void solve() {
        int n = ni();
        int m = ni();

        UnionFindTree uf = new UnionFindTree(n);

        for (int i = 0; i < m; i++) {
            int a = ni() - 1;
            int b = ni() - 1;
            uf.unite(a, b);
        }

        int min = 0;
        int[] count = new int[n];
        for (int i = 0; i < n; i++) {
            min = Math.max(min, uf.size(i));
        }

        for (int i : count) {
            min = Math.max(i, min);
        }

        out.println(min);
    }

    public static void main(String[] args) throws Exception {
        long S = System.currentTimeMillis();
        is = INPUT.isEmpty() ? System.in : new ByteArrayInputStream(INPUT.getBytes());
        out = new PrintWriter(System.out);

        solve();
        out.flush();
        long G = System.currentTimeMillis();
        tr(G-S+"ms");
    }

    private static boolean eof() {
        if(lenbuf == -1)return true;
        int lptr = ptrbuf;
        while(lptr < lenbuf)if(!isSpaceChar(inbuf[lptr++]))return false;

        try {
            is.mark(1000);
            while(true){
                int b = is.read();
                if(b == -1){
                    is.reset();
                    return true;
                }else if(!isSpaceChar(b)){
                    is.reset();
                    return false;
                }
            }
        } catch (IOException e) {
            return true;
        }
    }

    private static byte[] inbuf = new byte[1024];
    static int lenbuf = 0, ptrbuf = 0;

    private static int readByte() {
        if(lenbuf == -1)throw new InputMismatchException();
        if(ptrbuf >= lenbuf){
            ptrbuf = 0;
            try { lenbuf = is.read(inbuf); } catch (IOException e) { throw new InputMismatchException(); }
            if(lenbuf <= 0)return -1;
        }
        return inbuf[ptrbuf++];
    }

    private static boolean isSpaceChar(int c) { return !(c >= 33 && c <= 126); }

    private static int skip() { int b; while((b = readByte()) != -1 && isSpaceChar(b)); return b; }

    private static double nd() { return Double.parseDouble(ns()); }
    private static char nc() { return (char)skip(); }

    private static String ns() {
        int b = skip();
        StringBuilder sb = new StringBuilder();
        while(!(isSpaceChar(b))){
            sb.appendCodePoint(b);
            b = readByte();
        }
        return sb.toString();
    }

    private static char[] ns(int n) {
        char[] buf = new char[n];
        int b = skip(), p = 0;
        while(p < n && !(isSpaceChar(b))){
            buf[p++] = (char)b;
            b = readByte();
        }
        return n == p ? buf : Arrays.copyOf(buf, p);
    }

    private static char[][] nm(int n, int m) {
        char[][] map = new char[n][];
        for(int i = 0;i < n;i++)map[i] = ns(m);
        return map;
    }

    private static int[] na(int n) {
        int[] a = new int[n];
        for(int i = 0;i < n;i++)a[i] = ni();
        return a;
    }

    private static int ni() {
        int num = 0, b;
        boolean minus = false;
        while((b = readByte()) != -1 && !((b >= '0' && b <= '9') || b == '-'));
        if(b == '-'){
            minus = true;
            b = readByte();
        }

        while(true){
            if(b >= '0' && b <= '9'){
                num = num * 10 + (b - '0');
            }else{
                return minus ? -num : num;
            }
            b = readByte();
        }
    }

    private static long nl() {
        long num = 0;
        int b;
        boolean minus = false;
        while((b = readByte()) != -1 && !((b >= '0' && b <= '9') || b == '-'));
        if(b == '-'){
            minus = true;
            b = readByte();
        }

        while(true){
            if(b >= '0' && b <= '9'){
                num = num * 10 + (b - '0');
            }else{
                return minus ? -num : num;
            }
            b = readByte();
        }
    }

    private static void tr(Object... o) { if(INPUT.length() != 0)System.out.println(Arrays.deepToString(o)); }

    // Union-Find
    public static class UnionFindTree {

        /**
         * 各要素に関するデータをこの配列一つで管理する． もし Dat[i] < 0 であれば，i が属する集合の大きさは -Dat[i] であり，i
         * が属する集合の代表 (root) は i である． Dat[i] >= 0 であれば，i の親は Dat[i] である．
         */
        final int[] Dat;

        /**
         * 全部で n 要素ある素集合を管理する UnionFindTree を構築する．
         *
         * @param n 要素の種類数
         */
        public UnionFindTree(int n) {
            this.Dat = new int[n];
            Arrays.fill(Dat, -1);
        }

        /**
         * 元 {@code x} が属する集合の代表を amortized O(α(N)) で答える．
         *
         * @param x 代表を求めたい元
         * @return {@code x} が属する集合の代表
         */
        public int root(int x) {
            if (Dat[x] < 0) return x;
            Dat[x] = root(Dat[x]);
            return Dat[x];
        }

        /**
         * 元 {@code x} が属する集合と元 {@code y} が属する集合を amortized O(α(N)) で merge する．
         *
         * @param x
         * @param y
         * @return 元々同じ集合に属していれば {@code false}，そうでなければ {@code true}
         */
        public boolean unite(int x, int y) {
            int xr = root(x);
            int yr = root(y);
            if (xr == yr) return false;
            if (Dat[xr] > Dat[yr]) {
            int tmp = xr; xr = yr; yr = tmp;
            }
            Dat[xr] += Dat[yr];
            Dat[yr] = xr;
            return true;
        }

        /**
         * 元 {@code x} と元 {@code y} が属する集合が同じであるかを amortized O(α(N)) で判定する
         *
         * @param x
         * @param y
         * @return 同じ集合に属していれば {@code true}，そうでなければ {@code false}
         */
        public boolean isSame(int x, int y) {
            return root(x) == root(y);
        }

        /**
         * 元 {@code x} が属する集合のサイズを amortized O(α(N)) で求める．
         *
         * @param x
         * @return 元 {@code x} が属する集合のサイズ
         */
        public int size(int x) {
            return -Dat[root(x)];
        }
    }

    // Dijkstra
    // Return min distance from start to end O(ElogV) (negative cost is prohibited)
    // edge is int[3] array {from,to,cost}
    // edges is edge list from specific node
    // all_edges is Map<from node number,edges>
    static int dijkstra(Map<Integer,List<int[]>> all_edges,int start,int end,int max_node_number) {
        int[] distance = new int[max_node_number + 1];
        Arrays.fill(distance, -1);
        PriorityQueue<int[]> p_que = new PriorityQueue<>((a,b) -> ((distance[a[0]] + a[2]) - (distance[b[0]] + b[2])));
        distance[start] = 0;
        List<int[]> edges = all_edges.get(start);
        p_que.addAll(edges);
        while (distance[end] < 0) {
            int[] nearest_edge = p_que.poll();
            assert nearest_edge != null;
            if (distance[nearest_edge[1]] < 0) {
                distance[nearest_edge[1]] = distance[nearest_edge[0]] + nearest_edge[2];
                if (all_edges.containsKey(nearest_edge[1])) {
                    edges = all_edges.get(nearest_edge[1]);
                    for (int[] edge : edges) {
                        if (distance[edge[1]] < 0) p_que.add(edge);
                    }
                }
            }
        }
        return distance[end];
    }

    // Enumerate primes in [2, n] with O(n log log n)
    public static List<Integer> sieveOfEratosthenes(int n) {
        boolean[] isPrime = new boolean[n+1];
        Arrays.fill(isPrime, true);
        for (int i = 2; i * i <= n; i++) {
            if (isPrime[i]) {
                for (int j = i + i; j <= n; j += i) {
                    isPrime[j] = false;
                }
            }
        }
        List<Integer> primes = new ArrayList<>();
        for (int i = 2; i <= n; i++) {
            if (isPrime[i]) {
                primes.add(i);
            }
        }
        return primes;
    }

    // Count divisor
    public static int countDivisor(int n) {
        int[] list = new int[n + 1];
        Arrays.fill(list, 0);
        int num = n;
        for (int i = 2; i <= n; i++) {
            while (num % i == 0) {
                list[i] = list[i] + 1;
                num /= i;
            }
        }
        int ans = 1;
        for (int i : list) {
            ans *= (i + 1);
        }
        return ans;
    }
}


Measured memory_bytes: 43540