#include <fstream>
#include <vector>

using namespace std;

ifstream f ("dfs.in");
ofstream g ("dfs.out");
vector<int> vecini[100001];
int n, m, ncc;
bool viz[100001];

void df(int nod){
    viz[nod] = true;
    for(auto i:vecini[nod]){
        if(!viz[i])
            df(i);
    }
}

void citire(){
    int x, y;
    f >> n >> m;
    for(int i = 1; i <= m; i ++){
        f >> x >> y;
        vecini[x].push_back(y);
        vecini[y].push_back(x);
    }
}

int main()
{
    citire();
    for(int i = 1; i <= n; i ++){
        if(!viz[i]){
            df(i);
            ncc++;
        }
    }
    g << ncc;
    return 0;
}