#include <fstream>
#include <vector>

using namespace std;

ifstream cin("dfs.in");
ofstream cout("dfs.out");

vector<int> G[100001];
int n, m;
int vis[100001];

void dfs(int nod) {
    vis[nod] = 1;
    for(auto nodnou : G[nod]) {
        if(vis[nodnou] == 0) {
            dfs(nodnou);
        }
    }
}

int main() {
    cin >> n >> m;
    for(int i = 1; i <= m; ++i) {
        int x, y; cin >> x >> y;
        G[x].push_back(y);
        G[y].push_back(x);
    }

    int ans = 0;
    for(int i = 1; i <= n; ++i) {
        if(vis[i] == 0) {
            ans++;
            dfs(i);
        }
    }

    cout << ans << '\n';

    return 0;
    
}