import sys

from collections import deque



input = sys.stdin.readline



N, M = list(map(int, input().split()))

relations = [[] for _ in range(N)]

for _ in range(M):

    a, b = list(map(int, input().split()))

    a -= 1

    b -= 1

    relations[a].append(b)

    relations[b].append(a)



ans = 0

visited = set()

for i in range(N):

    q = deque()

    q.append(i)

    start = len(visited)

    while q:

        pos = q.popleft()

        if pos in visited:

            continue

        visited.add(pos)

        for n_pos in relations[pos]:

            if n_pos in visited:

                continue

            q.appendleft(n_pos)

    end = len(visited)

    ans = max(ans, end - start)



print(ans)
import sys



class UnionFind():

    def __init__(self, n):

        self.n = n

        self.parents = [-1] * n



    def find(self, x):

        if self.parents[x] < 0:

            return x

        else:

            self.parents[x] = self.find(self.parents[x])

            return self.parents[x]



    def union(self, x, y):

        x = self.find(x)

        y = self.find(y)



        if x == y:

            return



        if self.parents[x] > self.parents[y]:

            x, y = y, x



        self.parents[x] += self.parents[y]

        self.parents[y] = x



    def size(self, x):

        return -self.parents[self.find(x)]



    def same(self, x, y):

        return self.find(x) == self.find(y)



    def members(self, x):

        root = self.find(x)

        return [i for i in range(self.n) if self.find(i) == root]



    def roots(self):

        return [i for i, x in enumerate(self.parents) if x < 0]



    def group_count(self):

        return len(self.roots())



    def all_group_members(self):

        return {r: self.members(r) for r in self.roots()}



    def __str__(self):

        return '\n'.join('{}: {}'.format(r, self.members(r)) for r in self.roots())



input = sys.stdin.readline



N, M = list(map(int, input().split()))

relations = []

for _ in range(M):

    a, b = list(map(int, input().split()))

    a -= 1

    b -= 1

    relations.append((a, b))



uf = UnionFind(N)

for a, b in relations:

    uf.union(a, b)



ans = 0

for i in range(N):

    ans = max(ans, uf.size(i))

print(ans)
import sys
from collections import deque

input = sys.stdin.readline
N, M = list(map(int, input().split()))
relations = [[] for _ in range(N)]
for _ in range(M):
    a, b = list(map(int, input().split()))
    a -= 1
    b -= 1
    relations[a].append(b)
    relations[b].append(a)
ans = 0
visited = set()
for i in range(N):
    q = deque()
    q.append(i)
    start = len(visited)
    while q:
        pos = q.popleft()
        if pos in visited:
            continue
        visited.add(pos)
        for n_pos in relations[pos]:
            if n_pos in visited:
                continue
            q.appendleft(n_pos)
    end = len(visited)
    ans = max(ans, end - start)
print(ans)

import sys


class UnionFind:
    def __init__(self, n):
        self.n = n
        self.parents = [-1] * n

    def find(self, x):
        if self.parents[x] < 0:
            return x
        else:
            self.parents[x] = self.find(self.parents[x])
            return self.parents[x]

    def union(self, x, y):
        x = self.find(x)
        y = self.find(y)
        if x == y:
            return
        if self.parents[x] > self.parents[y]:
            x, y = y, x
        self.parents[x] += self.parents[y]
        self.parents[y] = x

    def size(self, x):
        return -self.parents[self.find(x)]

    def same(self, x, y):
        return self.find(x) == self.find(y)

    def members(self, x):
        root = self.find(x)
        return [i for i in range(self.n) if self.find(i) == root]

    def roots(self):
        return [i for i, x in enumerate(self.parents) if x < 0]

    def group_count(self):
        return len(self.roots())

    def all_group_members(self):
        return {r: self.members(r) for r in self.roots()}

    def __str__(self):
        return "\n".join("{}: {}".format(r, self.members(r)) for r in self.roots())


input = sys.stdin.readline
N, M = list(map(int, input().split()))
relations = []
for _ in range(M):
    a, b = list(map(int, input().split()))
    a -= 1
    b -= 1
    relations.append((a, b))
uf = UnionFind(N)
for a, b in relations:
    uf.union(a, b)
ans = 0
for i in range(N):
    ans = max(ans, uf.size(i))
print(ans)

-from collections import deque + + +class UnionFind: +    def __init__(self, n): +        self.n = n +        self.parents = [-1] * n + +    def find(self, x): +        if self.parents[x] < 0: +            return x +        else: +            self.parents[x] = self.find(self.parents[x]) +            return self.parents[x] + +    def union(self, x, y): +        x = self.find(x) +        y = self.find(y) +        if x == y: +            return +        if self.parents[x] > self.parents[y]: +            x, y = y, x +        self.parents[x] += self.parents[y] +        self.parents[y] = x + +    def size(self, x): +        return -self.parents[self.find(x)] + +    def same(self, x, y): +        return self.find(x) == self.find(y) + +    def members(self, x): +        root = self.find(x) +        return [i for i in range(self.n) if self.find(i) == root] + +    def roots(self): +        return [i for i, x in enumerate(self.parents) if x < 0] + +    def group_count(self): +        return len(self.roots()) + +    def all_group_members(self): +        return {r: self.members(r) for r in self.roots()} + +    def __str__(self): +        return "\n".join("{}: {}".format(r, self.members(r)) for r in self.roots()) + -relations = [[] for _ in range(N)] +relations = [] -    relations[a].append(b) -    relations[b].append(a) +    relations.append((a, b)) +uf = UnionFind(N) +for a, b in relations: +    uf.union(a, b) -visited = set() -    q = deque() -    q.append(i) -    start = len(visited) -    while q: -        pos = q.popleft() -        if pos in visited: -            continue -        visited.add(pos) -        for n_pos in relations[pos]: -            if n_pos in visited: -                continue -            q.appendleft(n_pos) -    end = len(visited) -    ans = max(ans, end - start) +    ans = max(ans, uf.size(i))