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

#define N_MAX 100005

ifstream cin{"dfs.in"};
ofstream cout{"dfs.out"};

int n, nr_comp;
vector<int> graf[N_MAX];
vector<int> d(N_MAX, -1);
int q[N_MAX];

void citeste() {
    int m;
    cin >> n >> m;

    while (m--){
        int i, j;
        cin >> i >> j;
        graf[i].push_back(j);
        graf[j].push_back(i);
    }
}

void BFS(int start) {
    int stg = 0, drp = 0;
    q[stg] = start;
    d[start] = 0;

    for (; stg <= drp; ++stg) {
        int current = q[stg];

        for (auto& nod : graf[current])
            if (nod != start && d[nod] == -1) {
                d[nod] = d[current] + 1;
                q[++drp] = nod;
            }
    }
}

void rezolva() {
    for (int i = 1; i <= n; ++i)
        if (d[i] == -1) {
            ++nr_comp;
            BFS(i);
        }
}

int main()
{
    citeste();
    rezolva();
    cout << nr_comp;
}