#include<fstream>
#include<vector>
#include<queue>
using namespace std;
ifstream fin("dfs.in");
ofstream fout("dfs.out");
vector <int> v[100001];
int n, m, i, j, viz[100001], a, b, k;

int dfs(int nod){
    viz[nod] = 1; int i;
    for (i = 0; i < v[nod].size(); i++)
        if (viz[v[nod][i]] == 0)
            dfs(v[nod][i]);
}

int main(){
    fin >> n >> m;
    for (i = 1; i <= m; i++){
        fin >> a >> b;
        v[a].push_back(b);
        v[b].push_back(a);
    }
    for (i = 1; i <= n; i++)
        if (viz[i] == 0){
            k++;
            dfs(i);
        }
    fout << k << '\n';
    fin.close();
    fout.close();
}