#include <list>
#include <vector>
#include <fstream>
#include <bitset>

constexpr int N = 1e5;
std::list<int> g[N];
std::bitset<N> vis;

void dfs(int x) {
    vis[x] = 1;
    for (auto y: g[x]) {
        vis[y] || (dfs(y), true);
    }
}

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

    int n, m;
    in >> n >> m;
    for (int i = 0; i < m; ++i) {
        int a, b;
        in >> a >> b;
        g[a].push_back(b);
        g[b].push_back(a);
    }
    
    int nc = 0;
    for (int i = 0; i < n; ++i) {
        if (!vis[i]) {
            ++nc;
            dfs(i);
        }
    }
    out << nc << '\n';
}