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

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

const int MAXN = 100005;
int n, m;
int sol;
vector<int> v[MAXN];
bool viz[MAXN];

void dfs(int k) {
    for (int i = 0; i < v[k].size(); ++i) {
        int node = v[k][i];
        if (viz[node] == 0) {
            viz[node] = 1;
            dfs(node);
        }
    }
}

int main() {

    fin >> n >> m;
    for (int i = 1; i <= m; ++i) {
        int a, b;
        fin >> a >> b;
        v[a].push_back(b);
        v[b].push_back(a);
    }

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

    fout << sol;

    fout.close();
    return 0;
}