
class Node
    attr_accessor :val
    def initialize(v, p)
        @val = v
        @parent = p
    end
    def root
        @parent == nil ? self : @parent.root
    end
end


n,m= gets.split(" ").map(&:to_i)
f = []
(1..m).each do
    a,b = gets.chomp.split(" ").map(&:to_i)
    f << [a-1,b-1].sort
end

class UnionFind
    # n:個数
    def initialize(n)
        @count = Array.new(n){|i| 1}
        @parent = Array.new(n){|i| i}
    end

    def root(i)
        if @parent[i] == i
            return i
        else
            r = self.root(@parent[i])
            if @count[i] > 0
                @count[r] += @count[i]
                @count[i] = 0
            end
            @parent[i] = r
            return @parent[i]
        end
    end

    def unite(a,b)
        a = self.root(a)
        b = self.root(b)
        if a != b
            @parent[b] = a
            @count[a] += @count[b]
            @count[b]=0
        end 
    end

    def show
        puts "parents"
        puts @parent.join(",")
        puts "count"
        puts @count.join(",")
    end 

    def max
        return @count.max
    end
end

un = UnionFind.new(n)
f.each do |p|
    un.unite(p[0], p[1])
end
puts un.max
#puts un.show
