#include <fstream>
#include <vector>

using namespace std;

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

const int N = 100010;

int n, m, i, j, x, y, nr;
bool viz[N];

vector<int> v[N];

void dfs(int x) {
    viz[x] = 1;
    for (int i = 0; i < v[x].size(); ++i)
        if (viz[v[x][i]] == 0) {
            dfs(v[x][i]);
        }
}

int main() {
    fin >> n >> m;
    for (i = 1; i <= m; ++i) {
        fin >> x >> y;
        v[x].push_back(y);
        v[y].push_back(x);
    }
    nr = 0;
    for (i = 1; i <= n; ++i)
        if(viz[i]==0) {
            nr++;
            dfs(i);
        }
    fout << nr << "\n";
    return 0;
}