#include <fstream>
#include <vector>
using namespace std;
#define DIM 100001

ofstream cout("dfs.out");
ifstream cin("dfs.in");

bool vf[DIM];
vector<int> graf[DIM];

bool dfs(int nod){
    vf[nod] = 1;
    for(auto newnod: graf[nod]){
        if(vf[newnod] == 0){
            dfs(newnod);
        }
    }
}

int main(void){
    int n, m;
    cin >> n >> m;
    for(int i = 1;i<=m;i++){
        int a, b;
        cin>> a >> b;
        graf[a].push_back(b);
        graf[b].push_back(a);
    }
    int cnt = 0;
    for(int i = 1;i<=n;i++){
        if(vf[i] == 0){
            cnt++;
            dfs(i);
        }
    }
    cout << cnt;
}