#include <fstream>
#include <vector>
#include <queue>

struct Node{
    std::vector<int> edges;
    int nrEdges;
    bool bejart;
    Node(){
        bejart = false;
        nrEdges = 0;
    }
    void addEdge(int x){
        edges.push_back(x);
        nrEdges++;
    }
    
};

void dfs(std::vector<Node> & nodes, int x){
    nodes[x].bejart = true;
    for(int i = 0; i < nodes[x].nrEdges; i++)
        if(!nodes[nodes[x].edges[i]].bejart)
            dfs(nodes, nodes[x].edges[i]);
}

int main() {
    std::ifstream bem("dfs.in");
    std::ofstream kim("dfs.out");
    int n, m;
    bem >> n >> m;
    std::vector<Node> nodes(n);
    for(int i = 0; i < m; i++){
        int x, y;
        bem >> x >> y;
        x--;
        y--;
        nodes[x].addEdge(y);
        nodes[y].addEdge(x);
    }

    int nr = 0;

    for(int i = 0; i < n; i++){
        if(!nodes[i].bejart){
            dfs(nodes, i);
            nr++;
        }
    }
    kim << nr;
    bem.close();
    kim.close();
}