#include <fstream>
#include <vector>
#define MAX 100004

using namespace std;

vector<int> v[MAX];

int n, m, k;
int vis[MAX];

void read();
void dfs(int x);

int main(){
    read();
    for (int i = 1; i <= n; ++i)
        if (!vis[i])
            dfs(i),
            ++k;
    ofstream fout ("dfs.out");
    fout << k << "\n";
    fout.close();
    return 0;
}

void read(){
    ifstream fin ("dfs.in");
    fin >> n >> m;
    int x, y;
    for (int i = 1; i <= m; ++i){
        fin >> x >> y;
        v[x].push_back(y);
        v[y].push_back(x);
    }
    fin.close();
}

void dfs(int x){
    vis[x] = 1;
    for (int i = 0; i < v[x].size(); ++i){
        if (vis[v[x][i]])
            continue;
        dfs(v[x][i]);
    }
}