#include <fstream>
#include <vector>
#define N 100005

using namespace std;

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

vector <int> muchii[N];
int viz[N], n, m, cate;

void DFS(int nod) {

    int i;

    viz[nod] = 1;
    for( auto i: muchii[nod])
        if(viz[i] == 0)
            DFS(i);
}

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

    for (int i = 1; i <= n; i++)
        if (viz[i] == 0) {
            cate++;
            DFS(i);
        }

    fout << cate << "\n";

    return 0;
}