import java.io.*
import java.util.*
import java.lang.*
import java.lang.Math.*

class UnionFind(val N: Int) {
    private val dt = IntArray(N+1){-1}
    fun root(key: Int): Int {
        if (this.dt[key] < 0) {
            return key
        } else {
            this.dt[key] = this.root(this.dt[key])
            return this.dt[key]
        }
    }
    fun unite(KX: Int, KY: Int): Boolean {
        var kx = this.root(KX); var ky = this.root(KY)
        if (kx == ky) {
            return false
        }
        if (this.size(kx) < this.size(ky)) {
            val tmp = kx
            kx = ky
            ky = tmp
        }
        this.dt[kx] += this.dt[ky]
        this.dt[ky] = kx
        return true;
    }
    fun size(key: Int): Int {
        val rk = this.root(key)
        return -this.dt[rk]
    }
    fun isConnect(kx: Int, ky: Int): Boolean {
        return this.root(kx) == this.root(ky)
    }
}

fun solve() {
    val (N, M) = rd.readIntArray()
    val uf = UnionFind(N)
    for (i in 0 until M) {
        val (a, b) = rd.readIntArray()
        uf.unite(a, b)
    }

    var ans = 0
    for (i in 0 until N) {
        ans = max(ans, uf.size(i))
    }

    println(ans)
}


//val rd = debug.Reader("abc", "177", "d", "sample-1")
val rd = Reader()


fun main(args: Array<String>) {
    try {
        var exception: Throwable? = null
        val sth = Thread(null, SolveThread(), "solveThread", 128 * 1024 * 1024)
        sth.setUncaughtExceptionHandler { _, e -> exception = e }
        sth.start(); sth.join()
        if (exception != null) throw exception!! }
    catch (e: Exception) { throw e }
    finally { rd.close() }
}
const val MOD = 1_000_000_007L; const val INF = Int.MAX_VALUE/2; const val LINF = Long.MAX_VALUE/2
val EPS = 1e-9; fun DBLEQ(a: Double, b: Double): Boolean {return abs(a - b) < EPS}
data class IntPair(val first: Int, val second: Int); data class LongPair(val first: Long, val second: Long)
data class To(val idx: Int, val cost: Long)
fun <T>edge(V: Int): Array<ArrayList<T>> { return Array(V){ArrayList<T>()} }
val errPrintln: (Any) -> Unit = { msg -> System.err.println(msg) }
fun rAssert(exp: Boolean, lazyMsg: () -> String = {""}) {
    if (!exp) { val msg = lazyMsg(); errPrintln("EAssert Error: $msg"); throw Error(msg) }
}
fun tAssert(exp: Boolean, lazyMsg: () -> String = {""}) {
    if (!exp) { val msg = lazyMsg(); errPrintln("TAssert Error: $msg"); Thread.sleep(3000) }
}
class SolveThread : Runnable {
    override fun run() { solve() }
}
class Reader {
    private val br = BufferedReader(InputStreamReader(System.`in`))
    val readString: () -> String = { br.readLine() }
    val readInt: () -> Int = { br.readLine().toInt() }
    val readLong: () -> Long = { br.readLine().toLong() }
    val readIntArray: () -> IntArray = { br.readLine().split(' ').map { it.toInt() }.toIntArray() }
    val readLongArray: () -> LongArray = { br.readLine().split(' ').map { it.toLong() }.toLongArray() }
    val readListInt: () -> List<Int> = { br.readLine().split(' ').map { it.toInt() } }
    val readListLong: () -> List<Long> = { br.readLine().split(' ').map { it.toLong() } }
    val readListIntCol: (Int) -> List<Int> = { N -> (0 until N).map { readInt() } }
    val readListLongCol: (Int) -> List<Long> = { N -> (0 until N).map { readLong() } }
    val close: () -> Unit = { br.close() }
    protected fun finalize() { close() }
}


Measured memory_bytes: 62292