#include <fstream>
#include <vector>

using namespace std;

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

vector<int> L[100001];
int vis[100001];

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 a, b;
        fin >> a >> b;
        L[a].push_back(b);
        L[b].push_back(a);
    }
    int nr = 0;
    for (int i = 1; i <= n; i ++) {
        if (vis[i] == 0) {
            nr++;
            dfs(i);
        }
    }
    fout << nr << endl;
    return 0;
}