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

using namespace std;

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

int n, m, nr_conexe;
bool sir[100005];
vector<int> mat[100005];

void dfs(int p) {
    if (sir[p] == 0) {
        sir[p] = 1;
        for (int i = 0; i < mat[p].size(); ++i) {
            if (sir[mat[p][i]] == 0) {
                dfs(mat[p][i]);
            }
        }
    }
}

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

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

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

    fout << nr_conexe;

    return 0;
}