#include <bits/stdc++.h>

using namespace std;

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

const int NMAX = 1e5;
vector<int> G[NMAX + 1];
int vis[NMAX + 1];

void dfs(int node) {
    vis[node] = 1;
    for(auto it : G[node]) {//for(int i = 0; i < G[node].size(); i++)
        if(!vis[it]) {
            dfs(it);
        }
    }
}

int main() {
    int n, m;
    f >> n >> m;
    for(int i = 1; i <= m; i++) {
        int a, b;
        f >> a >> b;
        G[a].push_back(b);
        G[b].push_back(a);
    }
    int cnt = 0;
    for(int i = 1; i <= n; i++) {
        if(!vis[i]) {
            cnt++;
            dfs(i);
        }
    }
    g << cnt;
    return 0;
}