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

int n, m, nr;
vector<int> L[100001];
int viz[100001];

void DFS(int nod) {
    viz[nod] = 1;
    for (auto vecin : L[nod])
        if (!viz[vecin])
            DFS(vecin);
}

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

    fin >> n >> m;

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

    for (int i = 1; i <= n; i++)
        if (!viz[i]) {
            nr++;
            DFS(i);
        }

    fout << nr;
    return 0;
}