import java.io.OutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.io.BufferedWriter;
import java.io.Writer;
import java.io.OutputStreamWriter;
import java.util.InputMismatchException;
import java.io.IOException;
import java.io.InputStream;

/**
 * Built using CHelper plug-in
 * Actual solution is at the top
 */
public class Main {
    public static void main(String[] args) {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        InputReader in = new InputReader(inputStream);
        OutputWriter out = new OutputWriter(outputStream);
        TaskD solver = new TaskD();
        solver.solve(1, in, out);
        out.close();
    }

    static class TaskD {
        public void solve(int testNumber, InputReader in, OutputWriter out) {
            int N = in.nextInt();
            int M = in.nextInt();
            TaskD.UnionFind uf = new TaskD.UnionFind(N);
            int x, y;
            for (int i = 0; i < M; ++i) {
                x = in.nextInt();
                y = in.nextInt();
                uf.union(x, y);
            }
            int ans = 0;
            for (int i = 1; i <= N; ++i) {
                ans = Math.max(ans, uf.size(i));
            }
            out.print(ans);
        }

        private static class UnionFind {
            private int[] parent;
            private int[] sz;

            public UnionFind(int size) {
                parent = new int[size + 1];
                sz = new int[size + 1];
                for (int i = 1; i < size + 1; ++i) {
                    parent[i] = i;
                    sz[i] = 1;
                }
            }

            private int size(int root) {
                return sz[find(root)];
            }

            private int find(int p) {
                if (p != parent[p]) {
                    parent[p] = find(parent[p]);
                }
                return parent[p];
            }

            public void union(int i, int j) {
                int pRoot = find(i);
                int qRoot = find(j);
                if (pRoot == qRoot) {
                    return;
                }
                if (sz[pRoot] > sz[qRoot]) {
                    parent[qRoot] = pRoot;
                    sz[pRoot] += sz[qRoot];
                } else {
                    parent[pRoot] = qRoot;
                    sz[qRoot] += sz[pRoot];
                }
            }

        }

    }

    static class OutputWriter {
        private final PrintWriter writer;

        public OutputWriter(OutputStream outputStream) {
            writer = new PrintWriter(new BufferedWriter(new OutputStreamWriter(outputStream)));
        }

        public OutputWriter(Writer writer) {
            this.writer = new PrintWriter(writer);
        }

        public void close() {
            writer.close();
        }

        public void print(int i) {
            writer.print(i);
        }

    }

    static class InputReader {
        private InputStream stream;
        private byte[] buf = new byte[1024];
        private int curChar;
        private int numChars;
        private InputReader.SpaceCharFilter filter;

        public InputReader(InputStream stream) {
            this.stream = stream;
        }

        public int read() {
            if (numChars == -1) {
                throw new InputMismatchException();
            }
            if (curChar >= numChars) {
                curChar = 0;
                try {
                    numChars = stream.read(buf);
                } catch (IOException e) {
                    throw new InputMismatchException();
                }
                if (numChars <= 0) {
                    return -1;
                }
            }
            return buf[curChar++];
        }

        public int nextInt() {
            int c = read();
            while (isSpaceChar(c)) {
                c = read();
            }
            int sgn = 1;
            if (c == '-') {
                sgn = -1;
                c = read();
            }
            int res = 0;
            do {
                if (c < '0' || c > '9') {
                    throw new InputMismatchException();
                }
                res *= 10;
                res += c - '0';
                c = read();
            } while (!isSpaceChar(c));
            return res * sgn;
        }

        public boolean isSpaceChar(int c) {
            if (filter != null) {
                return filter.isSpaceChar(c);
            }
            return isWhitespace(c);
        }

        public static boolean isWhitespace(int c) {
            return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
        }

        public interface SpaceCharFilter {
            public boolean isSpaceChar(int ch);

        }

    }
}



Measured memory_bytes: 38144