#include <fstream>
#include <vector>

#define maxn 100010

using namespace std;

vector<int> a[maxn];
int n, m;
bool seen[maxn];

void dfs(int node) {

    seen[node] = true;
    for (int i = 0; i < a[node].size(); i++) {
        if (!seen[a[node][i]])
            dfs(a[node][i]);
    }
}

int main() {
    ifstream in("dfs.in");
    ofstream out("dfs.out");

    int x, y, sol = 0;

    in >> n >> m;

    for (int i = 0; i < m; i++) {
        in >> x >> y;
        a[x].push_back(y);
        a[y].push_back(x);
    }

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

    out << sol;
    return 0;
}