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

ifstream fin("dfs.in");
ofstream fout("dfs.out");
int viz[1000001];
vector <int> a[100001];

void dfs(int nod){
   viz[nod]=1;
    for (vector <int> :: iterator i =a[nod].begin(); i != a[nod].end(); i++)
        if(viz[*i] == 0)
            dfs(*i);

}
int main(){
    int n,m;
    int x,y;
    fin>>n>>m;
    while(m){
        fin>>x>>y;
        a[x].push_back(y);
        a[y].push_back(x);
        m--;
    }
    int nr = 0;
    for(int i=1;i<=n;i++)
    {
        if(viz[i] == 0)
        {
            nr++;
            dfs(i);
        }
    }
    fout<<nr;
}