#include <fstream>
#include <vector>
#include <stack>

using namespace std;

/*ifstream cin ("input");
ofstream cout ("output");*/

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

vector < vector < int > > gr (100100);
vector < int > used (100100);
stack < int > Q;

void dfs_it (int root){
    Q.push(root);
    while (!Q.empty()){
        int now = Q.top();
        Q.pop();
        if (used[now]){
            continue;
        }
        used[now] = true;
        for (int i=gr[now].size() - 1; i>=0; i--){
            if (!used[gr[now][i]]){
                Q.push(gr[now][i]);
            }
        }
    }
}

int main() {

    ios::sync_with_stdio(false);
    cin.tie(NULL);

    int nodes , edges;
    cin>>nodes>>edges;

    for (int i=1; i<=edges; i++){
        int a , b;
        cin>>a>>b;
        gr[a].push_back(b);
        gr[b].push_back(a);
    }

    int cont = 0;

    for (int i=1; i<=nodes; i++){
        if (!used[i]){
            cont ++;
            dfs_it(i);
        }
    }

    cout<<cont;

    return 0;
}