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

using namespace std;

#define MAX 100005

vector <int> v[MAX];
int visited[MAX];

void dfs(int n) {
    visited[n] = 1;
    for (int i = 0; i < v[n].size(); ++i)
        if (!visited[v[n][i]])
            dfs(v[n][i]);
}

int main()
{
    ifstream f("dfs.in");
    ofstream g("dfs.out");

    int n, m, x, y;
    f >> n >> m;

    for (int i = 1; i <= m; i++) {
        f >> x >> y;
        v[x].push_back(y);
        v[y].push_back(x);
    }

    int cnt=0;

    for (int i = 1; i <= n; ++i) {
        if (visited[i] == 0) {
            dfs(i);
            cnt++;
        }
    }

    g << cnt;

    f.close();
    g.close();
    return 0;
}