#include <iostream>
#include <fstream>
#include <vector>
using namespace std;
ifstream fin("dfs.in");
ofstream fout("dfs.out");
int n, m, a, b, rasp;
vector<int> v[100010];
bool f[100010];

void dfs(int i) {
    for (int j = 0; j < v[i].size(); j++)
        if (!f[v[i][j]]) {
            f[v[i][j]] = true;
            dfs(v[i][j]);
        }
}

int main() {
    fin >> n >> m;

    for (int i = 1; i <= m; i++) {
        fin >> a >> b;
        v[a].push_back(b);
        v[b].push_back(a);
    }

    for (int i = 1; i <= n; i++)
        if (!f[i]) {
            rasp++;
            f[i] = true;
            dfs(i);
        }

    fout << rasp;
    return 0;
}