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

vector <int> a[100001];
int viz[100001], nc, n, m;

void DFS(int k)
{
    viz[k] = nc;
    for(auto it : a[k])
    {
        if(!viz[it])
            DFS(it);
    }
}

int main()
{
    fin >> n >> m;
    int x, y;
    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(!viz[i])
        {
            nc++;
            DFS(i);
        }
    }

    fout << nc;

    return 0;
}