#include <fstream>
#include <vector>
using namespace std;

ifstream f("dfs.in");
ofstream g("dfs.out");

vector <int> graph[100001];

int visited[100001];
vector <int> parcurgere;
void dfs(int node) {
    visited[node] = 1;

    for (auto vecin :graph[node]) {
        if (visited[vecin] == 1) continue;
        dfs(vecin);
    }
}

int main() {
    int N, M, x, y, cont=0;
    f>>N>>M;
    for(int i = 1; i<=M; i++){
        f>>x>>y;

        graph[x].push_back(y);
        graph[y].push_back(x);
    }
    for(int i = 1; i<=N; i++){
        if(visited[i] == 0){
            dfs(i);
            cont++;
        }
    }
    g<<cont;
    return 0;
}