#include <fstream>
#include <vector>

int sel[100001];
std::vector<std::vector<int>> graf(100001);

void dfs (const int &start) {
    sel[start] = 1;
    for (auto vecin : graf[start]) {
        if (!sel[vecin]) dfs(vecin);
    }
}

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

    int n, m;
    fin >> n >> m;

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

    int nr_comp = 0;
    for (int i = 1; i <= n; ++i) {
        if (!sel[i]) {
            ++nr_comp;
            dfs(i);
        }
    }

    fout << nr_comp;

    return 0;
}