#include <iostream>
#include <fstream>
#include <vector>
#define nmax 100005
using namespace std;

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

int n, m, rez;
bool VIZ[nmax];
vector <int> V[nmax];

void readData() {
    int i, a, b;
    fin >> n >> m;
    for (i = 1; i <= m; i++) {
        fin >> a >> b;
        V[a].push_back(b);
        V[b].push_back(a);
    }
}

void dfs(int nod) {
    int i;
    VIZ[nod] = true;
    for (i = 0; i < V[nod].size(); i++)
        if (!VIZ[V[nod][i]])
            dfs(V[nod][i]);
}

void solve() {
    int i;
    for (i = 1; i <= n; i++)
        if (!VIZ[i]) {
            rez++;
            dfs(i);
        }
}

void writeData() {
    fout << rez << "\n";
}

int main() {
    readData();
    solve();
    writeData();
    fin.close();
    fout.close();
    return 0;
}