#include <bits/stdc++.h>

using namespace std;

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

const int nlim = 100005;
int n, m, c;
bool viz[nlim];
vector <int> v[nlim];

void DFS(int nod) {
    viz[nod] = true;
    for (unsigned int i = 0; i < v[nod].size(); ++i) {
        int vecin = v[nod][i];
        if (!viz[vecin])
            DFS(vecin);
    }
}

void citire() {
    f >> n >> m;
    for (int i = 1; i <= m; ++i) {
        int x, y;
        f >> x >> y;
        v[x].push_back(y);
        v[y].push_back(x);
    }
    for (int i = 1; i <= n; ++i) {
        if (!viz[i]) {
            ++c;
            DFS(i);
        }
    }
}

int main()
{
    citire();
    g << c;
}