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

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

const int N = 1e5;
int n_vf , n_edgs;
vector<int> m[N + 1];
bool visited[N + 1];

void dfs(int x){
    visited[x] = true;
    for(int y = 0 ; y < m[x].size() ; y++){
        if(!visited[m[x][y]]){
            dfs(m[x][y]);
        }
    }
}


int main(){
    in >> n_vf >> n_edgs;
    for(int i = 1 ; i <= n_edgs ; i++){
        int x , y;
        in >> x >> y;
        m[x].push_back(y);
        m[y].push_back(x);
    }
    int cnt = 0;
    for(int i = 1 ; i <= n_vf ; i++){
        if(visited[i] == false){
            cnt++;
            dfs(i);
        }
    }
    out << cnt;

}