#include <fstream>
#include <vector>

using namespace std;

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

const int N=100001;

vector <int> a[N+1];
int n,m;
bool viz[N+1];

void citire(){
    cin>>n>>m;
    int i,x,y;
    for(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 i,y;
    for(i=0;i<a[x].size();i++){
        y=a[x][i];
        if(!viz[y]){
            dfs(y);
        }
    }
}

int main()
{
    citire();
    int sol=0;
    for(int i=1;i<=n;i++)
        if (viz[i]==0){
            dfs(i);
            sol++;
        }
    cout<<sol<<"\n";
    return 0;
}