from collections import deque



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

friends = [[] for _ in range(N+1)]

for __ in range(M):

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

  friends[a].append(b)

  friends[b].append(a)

checked = [0 for ___ in range(N+1)]

answer = 1

for i in range(1, N+1):

  friend = deque(friends[i])

  cnt = 0

  while(len(friend) > 0):

    f = friend.popleft()

    if checked[f] != 0:

      continue

    else:

      checked[f] = 1

      cnt += 1

      for ff in friends[f]:

        friend.append(ff)

  answer = max(answer, cnt)

print(answer)

  
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())



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

f_uf = UnionFind(N)

for _ in range(M):

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

  f_uf.union(a-1, b-1)

answer = 1

for i in range(N):

  answer = max(answer, f_uf.size(i))

print(answer)

from collections import deque

N, M = list(map(int, input().split()))
friends = [[] for _ in range(N + 1)]
for __ in range(M):
    a, b = list(map(int, input().split()))
    friends[a].append(b)
    friends[b].append(a)
checked = [0 for ___ in range(N + 1)]
answer = 1
for i in range(1, N + 1):
    friend = deque(friends[i])
    cnt = 0
    while len(friend) > 0:
        f = friend.popleft()
        if checked[f] != 0:
            continue
        else:
            checked[f] = 1
            cnt += 1
            for ff in friends[f]:
                friend.append(ff)
    answer = max(answer, cnt)
print(answer)

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())


N, M = list(map(int, input().split()))
f_uf = UnionFind(N)
for _ in range(M):
    a, b = list(map(int, input().split()))
    f_uf.union(a - 1, b - 1)
answer = 1
for i in range(N):
    answer = max(answer, f_uf.size(i))
print(answer)

-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()) + -friends = [[] for _ in range(N + 1)] -for __ in range(M): +f_uf = UnionFind(N) +for _ in range(M): -    friends[a].append(b) -    friends[b].append(a) -checked = [0 for ___ in range(N + 1)] +    f_uf.union(a - 1, b - 1) -for i in range(1, N + 1): -    friend = deque(friends[i]) -    cnt = 0 -    while len(friend) > 0: -        f = friend.popleft() -        if checked[f] != 0: -            continue -        else: -            checked[f] = 1 -            cnt += 1 -            for ff in friends[f]: -                friend.append(ff) -    answer = max(answer, cnt) +for i in range(N): +    answer = max(answer, f_uf.size(i))