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

ifstream f("dfs.in"); ofstream g("dfs.out");

vector <int> v[100005];
//vector <int> :: iterator it;
int viz[100005];
int i, j, n, m, x, y, r;

void dfs(int fx){
    viz[fx]=i;
    for (vector <int>::iterator it=v[fx].begin(); it!=v[fx].end(); it++){
        if (viz[(*it)]==0) dfs(*it);
    }
}


int main(){
    f>>n>>m;
    for (i=1; i<=m; i++){
        f>>x>>y;
        v[x].push_back(y);
        v[y].push_back(x);
    }

    for (i=1; i<=n; i++){
        if (viz[i]==0){
            r++;
            dfs(i);
        }
    }

    g<<r;
}