import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.Comparator;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Iterator;
import java.util.List;
import java.util.Map.Entry;
import java.util.PriorityQueue;
import java.util.Scanner;
import java.util.StringTokenizer;

class Main {
    static final int MOD = 1000000007;
    static final int INF = 1 << 30;
    static final int ALF = 26;

    Main() {
        FastScanner sc = new FastScanner(System.in);
        long ans = 0;
        int N = sc.nextInt();
        int M = sc.nextInt();
        UnionFindTree uf = new UnionFindTree(N);
        for(int i=0;i<M;i++){
            int a = sc.nextInt()-1;
            int b = sc.nextInt()-1;
            uf.union(a, b);
        }
        int[] C = new int[N];
        for(int i=0;i<N;i++){
            int f = uf.find(i);
            C[f]++;
        }
        int cnt=0;
        for(int i=0;i<N;i++){
            if(C[i]>0)cnt++;
            ans = Math.max(ans,C[i]);
        }
        System.out.println(ans);
    }

    public static void main(String[] args) {
        new Main();
    }
}

class FastScanner {
    private BufferedReader reader = null;
    private StringTokenizer tokenizer = null;

    public FastScanner(InputStream in) {
        reader = new BufferedReader(new InputStreamReader(in));
        tokenizer = null;
    }

    public String next() {
        if (tokenizer == null || !tokenizer.hasMoreTokens()) {
            try {
                tokenizer = new StringTokenizer(reader.readLine());
            } catch (IOException e) {
                throw new RuntimeException(e);
            }
        }
        return tokenizer.nextToken();
    }

    public String nextLine() {
        if (tokenizer == null || !tokenizer.hasMoreTokens()) {
            try {
                return reader.readLine();
            } catch (IOException e) {
                throw new RuntimeException(e);
            }
        }

        return tokenizer.nextToken("\n");
    }

    public long nextLong() {
        return Long.parseLong(next());
    }

    public int nextInt() {
        return Integer.parseInt(next());
    }

    public double nextDouble() {
        return Double.parseDouble(next());
    }

    public ArrayList<Integer> nextIntList(int n) {
        ArrayList<Integer> a = new ArrayList<Integer>(n);
        for (int i = 0; i < n; i++)
            a.add(nextInt());
        return a;
    }

    public ArrayList<Long> nextLongList(int n) {
        ArrayList<Long> a = new ArrayList<Long>(n);
        for (int i = 0; i < n; i++)
            a.add(nextLong());
        return a;
    }
    
    public int[] nextIntArray(int n) {
        int[] a = new int[n];
        for (int i = 0; i < n; i++)
            a[i] = nextInt();
        return a;
    }

    public long[] nextLongArray(int n) {
        long[] a = new long[n];
        for (int i = 0; i < n; i++)
            a[i] = nextLong();
        return a;
    }
}
class UnionFindTree {
    int[] parent;
    int[] rank;

    public UnionFindTree(final int size) {
        this.parent = new int[size + 1];
        this.rank = new int[size + 1];
        for (int i = 0; i <= size; i++) {
            parent[i] = i;
            rank[i] = 0;
        }
    }

    public void union(final int x, final int y) {
        final int xRoot = find(x);
        final int yRoot = find(y);

        if (rank[xRoot] > rank[yRoot]) {
            parent[yRoot] = xRoot;
        } else if (rank[xRoot] < rank[yRoot]) {
            parent[xRoot] = yRoot;
        } else if (xRoot != yRoot) {
            parent[yRoot] = xRoot;
            rank[xRoot]++;
        }
    }

    public int find(final int i) {
        if (i != parent[i]) {
            parent[i] = find(parent[i]);
        }
        return parent[i];
    }

    public boolean same(final int x, final int y) {
        return find(x) == find(y);
    }
}


Measured memory_bytes: 57988