#include <fstream>
#include <vector>
#include <iterator>
#define NMAX 100004
using namespace std;
int freq[NMAX]={0};

void DFS(vector<int> *a,int n,int current){
    freq[current] = 1;
    for(vector<int>::iterator it=a[current].begin();it!=a[current].end();it++)
        if(!freq[*it])
            DFS(a,n,*it);
}

int main()
{
    ifstream f("dfs.in");
    ofstream g("dfs.out");
    int n,m,m1,m2;
    vector<int> a[NMAX];
    f >> n >> m;
    for(int i=0;i<m;i++){
        f >> m1 >> m2;
        a[m1].push_back(m2);
        a[m2].push_back(m1);
    }
    int c=0;
    for(int i=1;i<=n;i++){
        if(!freq[i]) {
            c++;
            DFS(a,n,i);
        }
    }
    g << c;
    return 0;
}