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

#define NMAX 100002

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

bitset<NMAX> visited;
vector<int> graf[NMAX];

void DFS(int nod) {

    visited[nod] = 1;

    for (auto& adj: graf[nod]) {

        if (!visited[adj])
            DFS(adj);
    }
}

int main() {

    int N, M;

    fin >> N >> M;

    int x, y;
    while (M--) {

        fin >> x >> y;

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

    int componente = 0;
    for (int i = 1; i <= N; ++i)
        if (!visited[i]) {
            componente++;
            DFS(i);
        }

    fout << componente;

    return 0;
}