#include <fstream>
#include <vector>

#define MAXN 100005

using namespace std;

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

vector <int> graph[MAXN];

int viz[MAXN];

inline void DFS(int node) {
    viz[node] = 1;

    for (auto x : graph[node]) {
        if (!viz[x])
            DFS(x);
    }
}

inline void Read() {
    int N, M, sol = 0, x, y;

    fin >> N >> M;

    for (int i = 1; i <= M; i++) {
        fin >> x >> y;

        graph[x].push_back(y);
        graph[y].push_back(x);
    }

    for (int i = 1; i <= N; i++) {
        if (!viz[i]) {
            sol++;
            DFS(i);
        }
    }

    fout << sol;
}

int main () {
    Read();

    fin.close(); fout.close(); return 0;
}