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

using namespace std;

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

#define MAX 100001

int n, m, x, y, neigh, ans;
bool vizited[MAX];
vector <int> g[MAX];

void dfs(int nod) {
    vizited[nod] = true;

    for (unsigned int i = 0; i < g[nod].size(); ++i) {
        neigh = g[nod][i];

        if (!vizited[neigh])
            dfs(neigh);
    }
}

void read() {
    in >> n >> m;
    for (int i = 1; i <= m; ++i) {
        in >> x >> y;

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

int main() {
    read();

    for (int i = 1; i <= n; ++i)
        if (!vizited[i]) {
            ++ans;
            dfs(i);
        }

    out << ans;
    return 0;
}