#include <fstream>
#include <vector>
#include <algorithm>
using namespace std;
ifstream in("dfs.in");
ofstream out("dfs.out");

const int NMAX = 100001;
int N,M;
bool visited[NMAX];
vector <int> v[NMAX];

void readIn(){
    in >> N >> M;
    for(int i = 0 ; i < M ; i ++){
        int x,y;
        in >> x >> y;
        v[x].push_back(y);
        v[y].push_back(x);
    }
}

void dfs(int node){
    visited[node] = true;
    for(auto x : v[node]){
        if(!visited[x]){
            dfs(x);
        }
    }
}

int main(){
    readIn();
    int nr = 0;
    for(int i = 1; i <= N;i++){
        if(!visited[i]){
            dfs(i);
            nr++;
        }
    }
    out << nr;
}