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

ifstream fin("dfs.in");
ofstream fout("dfs.out");

int n,m;
int k=0;
bool vizitat[100000];
vector <int> edge[100000];

void DFS(int Nod)
{
    vizitat[Nod] = true;
    for(unsigned int i=0; i<edge[Nod].size();i++){
        int next = edge[Nod][i];
        if(!vizitat[next]){
            DFS(next);
        }
    }
}

int main()
{
    fin>>n>>m;
    for(int i=1;i<=m;i++){
        int x,y;
        fin>>x>>y;
        edge[x].push_back(y);
        edge[y].push_back(x);
    }
    for(int i=1;i<=n;i++){
        if(!vizitat[i]){
            k++;
            DFS(i);
        }
    }
    fout<<k;
    return 0;
}