#include <fstream>
#include <vector>

using namespace std;

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

vector<int> gr[100001];
int v[100001], n, m, comp;

void dfs(int x) {
    v[x] = 1;
    for (auto it : gr[x])
        if(!v[it])
            dfs(it);
}

int main() {
    fin >> n >> m;
    for (int a, b; m; m--) {
        fin >> a >> b;
        gr[a].push_back(b);
        gr[b].push_back(a);
    }
    for (int i = 1; i <= n; i++)
        if (!v[i]) {
            comp++;
            dfs(i);
        }
    fout << comp;
    return 0;
}