#include <iostream>
#include <vector>
#include <fstream>
const int N_MAX = 100005;

std :: vector <int> edge[N_MAX];
bool vis[N_MAX];
int n, m, nr;

void dfs(int node) {
    vis[node] = true;
    for (int i : edge[node]) {
        if (!vis[i])
            dfs(i);
    }
}

int main() {

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

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

    for (int j = 1; j <= n; ++j) {
        if (!vis[j]) {
            nr++;
            dfs(j);
        }
    }
    fout << nr;
    return 0;
}