#include <iostream>
#include <fstream>
#include <vector>
using namespace std;

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

int n, m;
vector<int> v[100005];
bool vizitat[100005];

void dfs(int x) {
    vizitat[x] = true;
    for (int y : v[x])
        if (!vizitat[y])
            dfs(y);
}

int main() {
    fin >> n >> m;
    for (int i = 0; i < m; i++) {
        int x, y;
        fin >> x >> y;
        v[x].push_back(y);
        v[y].push_back(x);
    }
    int comp = 0;
    for (int i = 1; i <= n; i++)
        if (!vizitat[i]) {
            comp++;
            dfs(i);
        }
    fout << comp << '\n';
    return 0;
}