#include <iostream>
#include <fstream>
#include <vector>
#include <stack>

using namespace std;

ifstream in("dfs.in");
ofstream out("dfs.out");

vector <int> G[100001];

int viz[100001];

int N, M;

void DFS(int nod)
{
    viz[nod] = 1;
    for (int i = 0; i < G[nod].size(); i++)
    {
        if (viz[G[nod][i]] == 0)
        {
            DFS(G[nod][i]);
        }
    }
}

int main()
{
    in >> N >> M;
    for (int i = 1; i <= M; i++)
    {
        int x, y;
        in >> x >> y;
        G[x].push_back(y);
        G[y].push_back(x);
    }
    int nr = 0;
    for (int i = 1; i <= N; i++)
    {
        if (viz[i] == 0)
        {
            nr++;
            DFS(i);
        }
    }
    out << nr;
    return 0;
}