import sys

sys.setrecursionlimit(10**7)



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

class UF():

  def __init__(self,par,rank):

    self.par = par

    self.rank = rank

  def find(self,x):

      if self.par[x] == x:

          return x

      else:

          self.par[x] = self.find(self.par[x]) #経路圧縮

          return self.par[x]

  def same(self,x,y):

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

  def unite(self,x,y):

      x = self.find(x)

      y = self.find(y)

      if x == y:

          return 0

      if self.rank[x] < self.rank[y]:

          self.par[x] = y

      else:

          self.par[y] = x

          if self.rank[x]==self.rank[y]:self.rank[x]+=1

uf=UF([i for i in range(N)],[0]*(N+1))

for _ in range(Q):

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

  a,b=a-1,b-1

  uf.unite(a,b)

from collections import Counter

a=[-1]*N

for i in range(N):

  a[i]=uf.find(i)

ca=Counter(a)

ans=0

for c in list(ca.values()):

  ans=max(ans,c)

print(ans)

import sys

sys.setrecursionlimit(10**7)



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



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())





uf=UnionFind(N)

for _ in range(Q):

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

  a,b=a-1,b-1

  uf.union(a,b)

from collections import Counter

a=[-1]*N

for i in range(N):

  a[i]=uf.find(i)

ca=Counter(a)

ans=0

for c in list(ca.values()):

  ans=max(ans,c)

print(ans)

import sys

sys.setrecursionlimit(10**7)
N, Q = list(map(int, input().split()))


class UF:
    def __init__(self, par, rank):
        self.par = par
        self.rank = rank

    def find(self, x):
        if self.par[x] == x:
            return x
        else:
            self.par[x] = self.find(self.par[x])  # 経路圧縮
            return self.par[x]

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

    def unite(self, x, y):
        x = self.find(x)
        y = self.find(y)
        if x == y:
            return 0
        if self.rank[x] < self.rank[y]:
            self.par[x] = y
        else:
            self.par[y] = x
            if self.rank[x] == self.rank[y]:
                self.rank[x] += 1


uf = UF([i for i in range(N)], [0] * (N + 1))
for _ in range(Q):
    a, b = list(map(int, input().split()))
    a, b = a - 1, b - 1
    uf.unite(a, b)
from collections import Counter

a = [-1] * N
for i in range(N):
    a[i] = uf.find(i)
ca = Counter(a)
ans = 0
for c in list(ca.values()):
    ans = max(ans, c)
print(ans)

import sys

sys.setrecursionlimit(10**7)
N, Q = list(map(int, input().split()))


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())


uf = UnionFind(N)
for _ in range(Q):
    a, b = list(map(int, input().split()))
    a, b = a - 1, b - 1
    uf.union(a, b)
from collections import Counter

a = [-1] * N
for i in range(N):
    a[i] = uf.find(i)
ca = Counter(a)
ans = 0
for c in list(ca.values()):
    ans = max(ans, c)
print(ans)

-class UF: -    def __init__(self, par, rank): -        self.par = par -        self.rank = rank +class UnionFind: +    def __init__(self, n): +        self.n = n +        self.parents = [-1] * n -        if self.par[x] == x: +        if self.parents[x] < 0: -            self.par[x] = self.find(self.par[x])  # 経路圧縮 -            return self.par[x] +            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 unite(self, x, y): -        x = self.find(x) -        y = self.find(y) -        if x == y: -            return 0 -        if self.rank[x] < self.rank[y]: -            self.par[x] = y -        else: -            self.par[y] = x -            if self.rank[x] == self.rank[y]: -                self.rank[x] += 1 +    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()) -uf = UF([i for i in range(N)], [0] * (N + 1)) +uf = UnionFind(N) -    uf.unite(a, b) +    uf.union(a, b)