#include<fstream>
#include<vector>

using namespace std;

const int MAX=1e5+1;

vector<int> a[MAX];
bool viz[MAX];

int n, m;

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

void citire(){
    cin>>n>>m;
    int x, y;
    for(int i=0; i<m; i++){
        cin>>x>>y;
        a[x].push_back(y);
        a[y].push_back(x);
    }
    cin.close();
}

void dfs(int x){
    viz[x]=true;
    int y;
    for(int i=0; i<a[x].size(); i++){
        y=a[x][i];
        if(viz[y]){
            dfs(y);
        }
    }
}

int main(){
    citire();
    int nr=0;
    for(int i=1; i<=n; i++){
        if(!viz[i]){
            dfs(i);
            ++nr;
        }
    }
    cout<<nr;
    cout.close();
    return 0;
}