#include <fstream>
#include <vector>

#define NMAX 100000
#define INF 100001

using namespace std;

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

int n, m;
bool ver[NMAX + 1];
vector <int> v[NMAX + 1];

void dfs(int nc) {
    ver[nc] = true;
    for (int j = 0; j < v[nc].size(); j++)
        if (!ver[v[nc][j]])
            dfs(v[nc][j]);
}

int main()
{
    fin >> n >> m;
    for (int i = 1; i <= m; i++) {
        int x, y;
        fin >> x >> y;
        v[x].push_back(y);
        v[y].push_back(x);
    }
    int nrcC = 0;
    for (int i = 1; i <= n; i++) {
        if (!ver[i]){
            nrcC++;
            dfs(i);
        }
    }
    fout << nrcC;
    return 0;
}