#include <bits/stdc++.h>
using namespace std;

const char iname[] = "dfs.in";
const char oname[] = "dfs.out";

#define INF (1 << 30)
static constexpr int NMAX = (int)1e5 + 5;

vector<int> adj[NMAX];

void dfs(int node, vector<bool>& visited) {
    visited[node] = true;

    for (auto& neigh : adj[node]) {
        if (!visited[neigh]) {
            dfs(neigh, visited);
        }
    }
}

int main() {
    ifstream in(iname);

    int N, M;
    in >> N >> M;

    for (int i = 1, x, y; i <= M; ++i) {
        in >> x >> y;
        adj[x].push_back(y);
        adj[y].push_back(x);
    }
    in.close();

    vector<bool> visited(N + 1);
    int conexComp = 0;

    for (int i = 1; i <= N; ++i) {
        if (!visited[i]) {
            dfs(i, visited);
            ++conexComp;
        }
    }

    ofstream out(oname);
    out << conexComp;
    out.close();

    return 0;
}