#include <fstream>
#include <vector>
#define NMAX 100005
using namespace std;
ifstream fin ("dfs.in");
ofstream fout("dfs.out");

int n, m, total;
bool d[NMAX];
vector<int> a[NMAX];

void DFS(int nod) {
    d[nod] = true;
    int x;
    for(int i=0; i<(int)a[nod].size(); i++) {
        x = a[nod][i];
        if(!d[x]) {
            DFS(x);
        }
    }
}

int main() {

    int x, y;
    fin >> n >> m;
    for(int i=1; i<=m; i++) {
        fin >> x >> y;
        a[x].push_back(y);
        a[y].push_back(x);
    }

    for(int i=1; i<=n; i++) {
        if(!d[i]) {
            total++;
            DFS(i);
        }
    }
    fout<<total;
    return 0;
}