#include <fstream>
#include <vector>
#include <stack>

std::ifstream input ("dfs.in");
std::ofstream output ("dfs.out");

int main () {

    int n, m;
    input >> n >> m;

    std::vector<std::vector<int>> graph(n + 1);
    for (int i = 0; i < m; ++i) {
        int x, y;
        input >> x >> y;
        graph[x].push_back(y);
        graph[y].push_back(x);
    }

    std::vector<bool> visited(n + 1, false);
    int componentCount = 0;
    for (int i = 1; i <= n; i++) {
        int currentComponentSize = 0;
        if (!visited[i]) {
            //output << "DFS started from node " << i << "\n";
            componentCount++;
            std::stack<int> stack;
            stack.push(i);
            visited[i] = true;

            while (!stack.empty()) {
                int currentNode = stack.top();
                stack.pop();
                currentComponentSize++;
                //output << currentNode << " ";

                for (int neighborNode : graph[currentNode]) {
                    if (!visited[neighborNode]) {
                        visited[neighborNode] = true;
                        stack.push(neighborNode);
                    }
                }
            }
            //output << "\n";            
        }
    }

    output << componentCount;

    return 0;
}