#include <iostream>
#include <vector>


using namespace std;



struct nod{
    int val;
    nod *next;
};
nod *lda[100001];
bool vz[100001];

void add(int x, int y)
{
    nod *newnod = new nod;
    newnod -> val = y;
    newnod ->next = nullptr;
    if (lda[x] == nullptr){
        lda[x] = newnod;
        return;
    }
    newnod -> next = lda[x];
    lda[x] = newnod;


}
void DFS(int ind)
{
    vz[ind] = 1;
    //cout << ind << "\n";
    for (nod *it = lda[ind]; it != nullptr; it = it ->next){
        if (!vz[it ->val]){
            DFS(it-> val);
        }
    }
}

int main()
{
    int rs = 0;
    int n;
    cin >> n;
    int m;
    cin >> m;
    for (int i = 0; i < m; i++){
        int x,y;
        cin >> x >> y;
        add(x,y);
        add(y,x);
    }
    for (int i = 1; i <= n; i++){
        if (!vz[i]){
            rs++;
            DFS(i);
        }
    }
    cout << rs << "\n";
    return 0;
}