#include <fstream>
#include <vector>
#define NMAX 100000

using namespace std;

vector<vector<int>> adj(NMAX + 1);
vector<bool> vis(NMAX + 1, 0);

void dfs(int node) {
    vis[node] = true;
    int size = adj[node].size();
    if (!size)
        return;

    for (int i = 0; i < size; i++)
        if (!vis[adj[node][i]])
            dfs(adj[node][i]);
}

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

    int n, m, x, y, count = 0;

    fin >> n >> m;
    for (int i = 0; i < m; i++) {
        fin >> x >> y;
        adj[x].push_back(y);
        adj[y].push_back(x);
    }
    
    for (int i = 1; i <= n; i++)
        if (!vis[i]) {
            count++;
            dfs(i);
        }

    fout << count;

    return 0;
}