#include <fstream>
#include <vector>

using namespace std;

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

const int NMAX = 1e5 + 1;

int n, m;
vector<int> v[NMAX];
bool viz[NMAX];

void dfs(int x) {
    viz[x] = 1;
    for (const int& y: v[x]) {
        if (!viz[y]){
            viz[y] = 1;
            dfs(y);
        }
    }
}

int main() {
    fin >> n >> m;
    for (int x, y; m; --m) {
        fin >> x >> y;
        v[x].push_back(y);
        v[y].push_back(x);
    }
    int cc = 0;
    for (int i = 1; i <= n; ++i) {
        if (viz[i])
            continue;
        dfs(i);
        cc++;
    }
    fout << cc << '\n';
    return 0;
}