//Optional FAST

//#pragma GCC optimize("Ofast")
//#pragma GCC optimize("unroll-loops")
//#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,fma,abm,mmx,avx,avx2,tune=native")

//Required Libraries

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#include <ext/pb_ds/detail/standard_policies.hpp>

//Required namespaces

using namespace std;
using namespace __gnu_pbds;

//Required defines

#define endl '\n'

#define READ(X) cin>>X;
#define READV(X) long long X; cin>>X;
#define READAR(A,N) long long A[N]; for(long long i=0;i<N;i++) {cin>>A[i];}
#define rz(A,N) A.resize(N);
#define sz(X) (long long)(X.size())
#define pb push_back
#define pf push_front
#define fi first
#define se second
#define FORI(a,b,c) for(long long a=b;a<c;a++)
#define FORD(a,b,c) for(long long a=b;a>c;a--)

//Required typedefs

typedef tree<long long,null_type,less<long long>,rb_tree_tag,tree_order_statistics_node_update> ordered_set;
typedef tree<long long,null_type,greater<long long>,rb_tree_tag,tree_order_statistics_node_update> ordered_set1;
typedef long long ll;
typedef long double ld;
typedef pair<int,int> pii;
typedef pair<long long,long long> pll;

//Required Constants

const long long inf=(long long)1e18;
const long long MOD=(long long)(1e9+7);
const long long INIT=(long long)(1e6+1);
const long double PI=3.14159265358979;

// Required random number generators

// mt19937 gen_rand_int(chrono::steady_clock::now().time_since_epoch().count());
// mt19937_64 gen_rand_ll(chrono::steady_clock::now().time_since_epoch().count());

//Required Functions

ll power(ll x,ll y) 
{ 
    if (y == 0) 
        return 1; 
    ll p = power(x, y/2) % MOD; 
    p = (p * p) % MOD; 
  
    return (y%2 == 0)? p : (x * p) % MOD; 
}
ll modInverse(ll a) 
{ 
   return power(a,MOD-2); 
   
}

//Work

ll root[500001];
ll szr[500001];
void initialise()
{
    for (ll i = 0; i < 500001; ++i)
    {
        root[i]=i;
    }
    for (ll i = 0; i < 500001; ++i)
    {
        szr[i]=1;
    }
}
ll find_root(ll v)
{
    if(root[v]==v)
    {
        return v;
    }
    else
    {
        root[v]=find_root(root[v]);
        return root[v];
    }
}
bool find(ll a,ll b)
{
    return find_root(a)==find_root(b);
}
void _union(ll a,ll b)
{
    ll _rootA=find_root(a);
    ll _rootB=find_root(b);
    if(_rootA!=_rootB)
    {
        szr[_rootA]+=szr[_rootB];
        szr[_rootB]=0;
        root[_rootB]=_rootA;
    }
}

int main()
{
    #ifndef ONLINE_JUDGE
    if (fopen("INPUT.txt", "r"))
    {
        freopen ("INPUT.txt" , "r" , stdin);
        //freopen ("OUTPUT.txt" , "w" , stdout);
    }
    #endif
    ios::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);

    clock_t clk;
    clk = clock();
//-----------------------------------------------------------------------------------------------------------//

    initialise();
    READV(N);
    READV(M);
    ll ans=0;
    FORI(i,0,M)
    {
        READV(x);
        READV(y);
        _union(x,y);
    }
    FORI(i,1,N+1)
    {
        ans=max(ans,szr[i]);
    }
    cout<<ans<<endl;

//-----------------------------------------------------------------------------------------------------------//


    clk = clock() - clk;
    cerr << fixed << setprecision(6) << "Time: " << ((double)clk)/CLOCKS_PER_SEC << endl;

    return 0;
}

Measured memory_bytes: 11620