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

// complexitate O(n + m)

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

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

void dfs(int node) {
    vis[node] = 1;
    for (auto vec : L[node]) {
        if (vis[vec] == 0) {
            dfs(vec);
        }
    }
}

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

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

    fout << cc << "\n";

    fin.close();
    fout.close();
    return 0;
}