#include <iostream>
#include <fstream>
#include <vector>
#define nmax 100002

using namespace std;
vector <int> v[nmax];

int viz[nmax];

void dfs (int x) {
    viz[x] = 1;
    vector <int> :: iterator it;
    for (it = v[x].begin();it!=v[x].end();++it) {
            if (!viz[*it])
            dfs(*it);
    }
}
ifstream f("dfs.in");
ofstream g("dfs.out");
int main()
{
    int n, m;
    f >> n >> m;
    int x, y;
    for (int i = 1; i <= m; ++i) {
        f >> x >> y;
        v[x].push_back(y);
        v[y].push_back(x);
    }
    int cont = 0;
    for (int i = 1; i <= n; ++i) {
        if (!viz[i]) {
            dfs(i);
            cont++;
        }
    }
    g << cont;
    return 0;
}