#include <fstream>
#include <vector>
using namespace std;

void dfs(vector<int> G[], int node, bool seen[]) {
    seen[node] = true;
    for (int ne: G[node])
        if (!seen[ne])
            dfs(G, ne, seen);
}

int main() {
    ifstream f("dfs.in");
    ofstream g("dfs.out");
    int n, m, x, y, result = 0;
    f >> n >> m;
    vector<int> G[n + 1];
    bool seen[n + 1];
    for (int i = 1; i <= n; i++)
        seen[i] = false;
    for (int i = 0; i < m; i++) {
        f >> x >> y;
        G[x].push_back(y);
        G[y].push_back(x);
    }

    for (int i = 1; i <= n; i++)
        if (!seen[i]) {
            result++;
            dfs(G, i, seen);
        }

    g << result;

    f.close();
    g.close();
    return 0;
}