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

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

void dfs(const vector<vector<int>>& graf, const int n, vector<int>& f, const int nod) {
    f[nod]=1;
    for (auto vecin : graf[nod]) {
        if (!f[vecin])
            dfs(graf,n,f,vecin);
    }
}

int nr_comp_con(const vector<vector<int>> &graf, const int n) {
    int cnt = 0;
    vector<int> f(n+1, 0);
    for (int i = 1; i <= n; i++) {
        if (!f[i]) {
            dfs(graf,n,f,i);
            cnt++;
        }
    }
    return cnt;
}

int main() {
    int n,m;
    fin >> n >> m;
    vector<vector<int>> graf(n+1);
    for (int i = 0; i < m; i++) {
        int x,y;
        fin >> x >> y;
        graf[x].push_back(y);
        graf[y].push_back(x);
    }

    fout << nr_comp_con(graf,n);
    return 0;
}