#include <fstream>
#include <vector>

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

void dfs(int start, std::vector<int> &visited, const std::vector<std::vector<int>> &graph) {
    if (visited[start] != 1) {
        visited[start] = 1;
        for (int vecin : graph[start]) {
            if (visited[vecin] != 1) {
                dfs(vecin, visited, graph);
            }
        }
    }
}

int main() {
    int x, y, n, m, nrConex = 0;
    fin >> n >> m;
    std::vector<int> visited(n+1, 0);
    std::vector<std::vector<int>> nodesList(n+1);
    while (fin >> x >> y) {
        nodesList[x].push_back(y);
        nodesList[y].push_back(x);
    }
    for (int i = 1; i <= n; i++) {
        if (visited[i] != 1) {
            nrConex ++;
            dfs(i, visited, nodesList);
        }
    }
    fout << nrConex;
}