/*
URL:
https://atcoder.jp/contests/abc177/tasks/abc177_d
*/

package main

import (
	"bufio"
	"fmt"
	"io"
	"math"
	"os"
	"strconv"
)

var (
	n, m int
	A, B []int
)

func main() {
	n, m = readi2()
	for i := 0; i < m; i++ {
		a, b := readi2()
		a--
		b--
		A = append(A, a)
		B = append(B, b)
	}

	uf := NewUnionFind(n)
	for i := 0; i < m; i++ {
		a, b := A[i], B[i]
		uf.Unite(a, b)
	}

	ans := 0
	for i := 0; i < n; i++ {
		ms := uf.CcSize(i)
		ChMax(&ans, ms)
	}
	fmt.Println(ans)
}

// ChMax accepts a pointer of integer and a target value.
// If target value is LARGER than the first argument,
//	then the first argument will be updated by the second argument.
func ChMax(updatedValue *int, target int) bool {
	if *updatedValue < target {
		*updatedValue = target
		return true
	}
	return false
}

// 0-based
// uf := NewUnionFind(n)
// uf.Root(x) 			// Get root node of the node x
// uf.Unite(x, y) 	// Unite node x and node y
// uf.Same(x, y) 		// Judge x and y are in the same connected component.
// uf.CcSize(x) 		// Get size of the connected component including node x
// uf.CcNum() 			// Get number of connected components

// UnionFind provides disjoint set algorithm.
// Node id starts from 0 (0-based setting).
type UnionFind struct {
	parents []int
}

// NewUnionFind returns a pointer of a new instance of UnionFind.
func NewUnionFind(n int) *UnionFind {
	uf := new(UnionFind)
	uf.parents = make([]int, n)

	for i := 0; i < n; i++ {
		uf.parents[i] = -1
	}

	return uf
}

// Root method returns root node of an argument node.
// Root method is a recursive function.
func (uf *UnionFind) Root(x int) int {
	if uf.parents[x] < 0 {
		return x
	}

	// route compression
	uf.parents[x] = uf.Root(uf.parents[x])
	return uf.parents[x]
}

// Unite method merges a set including x and a set including y.
func (uf *UnionFind) Unite(x, y int) bool {
	xp := uf.Root(x)
	yp := uf.Root(y)

	if xp == yp {
		return false
	}

	// merge: xp -> yp
	// merge larger set to smaller set
	if uf.CcSize(xp) > uf.CcSize(yp) {
		xp, yp = yp, xp
	}
	// update set size
	uf.parents[yp] += uf.parents[xp]
	// finally, merge
	uf.parents[xp] = yp

	return true
}

// Same method returns whether x is in the set including y or not.
func (uf *UnionFind) Same(x, y int) bool {
	return uf.Root(x) == uf.Root(y)
}

// CcSize method returns the size of a set including an argument node.
func (uf *UnionFind) CcSize(x int) int {
	return -uf.parents[uf.Root(x)]
}

// CcNum method returns the number of connected components.
// Time complextity is O(n)
func (uf *UnionFind) CcNum() int {
	res := 0
	for i := 0; i < len(uf.parents); i++ {
		if uf.parents[i] < 0 {
			res++
		}
	}
	return res
}

/*******************************************************************/

/********** common constants **********/

const (
	// General purpose
	MOD = 1000000000 + 7
	// MOD          = 998244353
	ALPHABET_NUM = 26
	INF_INT64    = math.MaxInt64
	INF_BIT60    = 1 << 60
	INF_INT32    = math.MaxInt32
	INF_BIT30    = 1 << 30
	NIL          = -1

	// for dijkstra, prim, and so on
	WHITE = 0
	GRAY  = 1
	BLACK = 2
)

/********** bufio setting **********/

func init() {
	// bufio.ScanWords <---> bufio.ScanLines
	ReadString = newReadString(os.Stdin, bufio.ScanWords)
	stdout = bufio.NewWriter(os.Stdout)
}

/********** FAU standard libraries **********/

//fmt.Sprintf("%b\n", 255) 	// binary expression

/********** I/O usage **********/

//str := ReadString()
//i := ReadInt()
//X := ReadIntSlice(n)
//S := ReadRuneSlice()
//a := ReadFloat64()
//A := ReadFloat64Slice(n)

//str := ZeroPaddingRuneSlice(num, 32)
//str := PrintIntsLine(X...)

/*********** Input ***********/

var (
	// ReadString returns a WORD string.
	ReadString func() string
	stdout     *bufio.Writer
)

func newReadString(ior io.Reader, sf bufio.SplitFunc) func() string {
	r := bufio.NewScanner(ior)
	r.Buffer(make([]byte, 1024), int(1e+9)) // for Codeforces
	r.Split(sf)

	return func() string {
		if !r.Scan() {
			panic("Scan failed")
		}
		return r.Text()
	}
}

// readi returns an integer.
func readi() int {
	return int(readInt64())
}
func readi2() (int, int) {
	return int(readInt64()), int(readInt64())
}
func readi3() (int, int, int) {
	return int(readInt64()), int(readInt64()), int(readInt64())
}
func readi4() (int, int, int, int) {
	return int(readInt64()), int(readInt64()), int(readInt64()), int(readInt64())
}

// readll returns as integer as int64.
func readll() int64 {
	return readInt64()
}
func readll2() (int64, int64) {
	return readInt64(), readInt64()
}
func readll3() (int64, int64, int64) {
	return readInt64(), readInt64(), readInt64()
}
func readll4() (int64, int64, int64, int64) {
	return readInt64(), readInt64(), readInt64(), readInt64()
}

func readInt64() int64 {
	i, err := strconv.ParseInt(ReadString(), 0, 64)
	if err != nil {
		panic(err.Error())
	}
	return i
}

// readis returns an integer slice that has n integers.
func readis(n int) []int {
	b := make([]int, n)
	for i := 0; i < n; i++ {
		b[i] = readi()
	}
	return b
}

// readlls returns as int64 slice that has n integers.
func readlls(n int) []int64 {
	b := make([]int64, n)
	for i := 0; i < n; i++ {
		b[i] = readll()
	}
	return b
}

// ReadFloat64 returns an float64.
func ReadFloat64() float64 {
	return float64(readFloat64())
}

func readFloat64() float64 {
	f, err := strconv.ParseFloat(ReadString(), 64)
	if err != nil {
		panic(err.Error())
	}
	return f
}

// ReadFloatSlice returns an float64 slice that has n float64.
func ReadFloat64Slice(n int) []float64 {
	b := make([]float64, n)
	for i := 0; i < n; i++ {
		b[i] = ReadFloat64()
	}
	return b
}

// ReadRuneSlice returns a rune slice.
func ReadRuneSlice() []rune {
	return []rune(ReadString())
}

/*********** Output ***********/

// PrintIntsLine returns integers string delimited by a space.
func PrintIntsLine(A ...int) string {
	res := []rune{}

	for i := 0; i < len(A); i++ {
		str := strconv.Itoa(A[i])
		res = append(res, []rune(str)...)

		if i != len(A)-1 {
			res = append(res, ' ')
		}
	}

	return string(res)
}

// PrintIntsLine returns integers string delimited by a space.
func PrintInts64Line(A ...int64) string {
	res := []rune{}

	for i := 0; i < len(A); i++ {
		str := strconv.FormatInt(A[i], 10) // 64bit int version
		res = append(res, []rune(str)...)

		if i != len(A)-1 {
			res = append(res, ' ')
		}
	}

	return string(res)
}

// PrintfBufStdout is function for output strings to buffered os.Stdout.
// You may have to call stdout.Flush() finally.
func PrintfBufStdout(format string, a ...interface{}) {
	fmt.Fprintf(stdout, format, a...)
}

/*********** Debugging ***********/

// PrintfDebug is wrapper of fmt.Fprintf(os.Stderr, format, a...)
func PrintfDebug(format string, a ...interface{}) {
	fmt.Fprintf(os.Stderr, format, a...)
}

// ZeroPaddingRuneSlice returns binary expressions of integer n with zero padding.
// For debugging use.
func ZeroPaddingRuneSlice(n, digitsNum int) []rune {
	sn := fmt.Sprintf("%b", n)

	residualLength := digitsNum - len(sn)
	if residualLength <= 0 {
		return []rune(sn)
	}

	zeros := make([]rune, residualLength)
	for i := 0; i < len(zeros); i++ {
		zeros[i] = '0'
	}

	res := []rune{}
	res = append(res, zeros...)
	res = append(res, []rune(sn)...)

	return res
}


Measured memory_bytes: 15264