#include <fstream>
#include <vector>

using namespace std;

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

vector <int> lista[100001];
int viz[100001];

int n, m;

void dfs(int nod){
    viz[nod] = 1;
    vector <int> :: iterator it;
    for(it = lista[nod].begin(); it != lista[nod].end(); it++)
        if(!viz[*it])
            dfs(*it);
}

int main()
{
    in >> n >> m;
    int cnt = 0;

    for(int i = 1; i <= m; i++){
        int x, y; in >> x >> y;
        lista[x].push_back(y);
        lista[y].push_back(x);
    }
    for(int i = 1; i <= n; i++)
        if(!viz[i]) cnt++, dfs(i);
    out << cnt;
    return 0;
}