#include <bits/stdc++.h>

#define N_MAX 100005

using namespace std;

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

int N, M;
vector <int> G[N_MAX];
bool vis[N_MAX];

void DFS(int node)
{
    vis[node] = true;
    for(auto it : G[node]) {
        if(!vis[it]) {
            DFS(it);
        }
    }
}

int main()
{
    fin >> N >> M;
    for(int i = 1; i <= M; i++) {
        int x, y;
        fin >> x >> y;
        G[x].push_back(y);
        G[y].push_back(x);
    }

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

    fout << cnt << "\n";

    return 0;
}