using System;
using System.Collections.Generic;
using System.Linq;
using static System.Console;
using static System.Convert;
using static System.Math;
//using Debug;
//using static System.Globalization.CultureInfo;
//using Edge = Pair<long, int>;
using System.Text;
class Program
{ 
    static void Main(string[] args)
    {
        Solve();
        //WriteLine(Solve());
    }
    static void Solve()
    {
        /*var nk = Input.ar;var res = 0L;
        for(var i = 1; i <= nk[0]; i++)
        {
            var ct = 0;var k = i;
            while (nk[1] > k) { k *= 2;ct++; }
            if(ct!=0)
            res += ct + 1;
        }
        WriteLine(((double) / res).ToString("F10"));*/
        var nm = Input.ar;
        var uf = new UnionFind(nm[0]);
        for(var i=0;i<nm[1];i++)
        {
            var xyz = Input.ar;
            uf.Union(xyz[0] - 1, xyz[1] - 1);
        }
        var set = new HashSet<int>();
        for (var i = 0; i < nm[0]; i++)
            set.Add(uf.Parent(i));
        WriteLine(set.Count);
    }
}

public class Input
{
    public static string read => ReadLine().Trim();
    public static int[] ar => read.Split(' ').Select(int.Parse).ToArray();
    public  static int num => ToInt32(read);
    public static long[] arL => read.Split(' ').Select(long.Parse).ToArray();
    public  static long numL => ToInt64(read);
    public static char[][] gred(int h) 
        => Enumerable.Repeat(0, h).Select(_ => read.ToCharArray()).ToArray();
    public static int[] ar1D(int n)
        => Enumerable.Repeat(0, n).Select(_ => num).ToArray();
    public static long[] arL1D(int n)
        => Enumerable.Repeat(0, n).Select(_ => numL).ToArray();
    public static int[][] ar2D(int n)
        => Enumerable.Repeat(0, n).Select(_ => ar).ToArray();
    public static long[][] arL2D(int n)
        => Enumerable.Repeat(0, n).Select(_ => arL).ToArray();
    public static T getValue<T>(string g)
    {
        var t = typeof(T);
        if (t == typeof(int))
            return (T)(object)int.Parse(g);
        if (t == typeof(long))
            return (T)(object)long.Parse(g);
        if (t == typeof(string))
            return (T)(object)g;
        if (t == typeof(char))
            return (T)(object)char.Parse(g);
        if (t == typeof(double))
            return (T)(object)double.Parse(g);
        if (t == typeof(bool))
            return (T)(object)bool.Parse(g);
        return default(T);
    }
    public const long Inf = (long)1e18;
    public const double eps = 1e-6;
    public  const string Alfa = "abcdefghijklmnopqrstuvwxyz";
    public  const int MOD = 1000000007;
}

public class UnionFind
{
    private int _num;
    private int[] _parent, _size, _rank;
    public UnionFind(int num)
    {
        _num = num;
        _parent = new int[num];_size = new int[num];_rank = new int[num];
        for(var i = 0; i < num; i++) { _parent[i] = i;_size[i] = 1;}
    }
    private int Find(int i)
        => i == _parent[i] ? i : (_parent[i] = Find(_parent[i]));
    public int Parent(int i)
        => Find(i);
    public int Size(int i)
        => _size[Find(i)];
    public bool Union(int v1,int v2)
    {
        v1 = Find(v1);v2 = Find(v2);
        if (v1==v2) return false;
        _num--;
        if (_rank[v1] > _rank[v2])
        {
            _parent[v2] = v1;
            _size[v1] += _size[v2];
        }
        else
        {
            _parent[v1] = v2;
            _size[v2] += _size[v1];
            if (_rank[v1] == _rank[v2])
                _rank[v2]++;
        }
        return true;
    }
    public bool IsSame(int v1, int v2)
        => Find(v1) == Find(v2);
}


Measured memory_bytes: 20660