#include <fstream>
#include <vector>

using namespace std;

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

vector <int> G[200001];
int viz[200001];
int n, m, x, y, nrc;

int dfs(int v)
{
    viz[v] = 1;
    for (unsigned int i = 0; i < G[v].size(); i++)
    {
        if (!viz[G[v][i]])
        {
            dfs(G[v][i]);
        }
    }
}

int main()
{
    cin >> n >> m;
    while (m--)
    {
        cin >> x >> y;
        G[x].push_back(y);
        G[y].push_back(x);
    }
    for (int i = 1; i <= n; i++)
    {
        if (viz[i] == 0)
        {
            nrc++;
            dfs(i);
        }
    }
    cout << nrc;
    return 0;
}