#include <fstream>
#include <vector>
using namespace std;

ifstream is("dfs.in");
ofstream os("dfs.out");

vector<vector<int>> g;
vector<bool> v;
int n, m;

void Write();
int Df(int x);
void Read();

int main()
{
    Read();
    int k = 0;
    for(int i = 1; i <= n; ++i)
    {
        if(!v[i])
        {
            ++k;
            Df(i);
        }

    }
    os << k;
    is.close();
    os.close();
    return 0;

}

void Read()
{
    is >> n;
    is >> m;
    g = vector<vector<int>>(n+1);
    v = vector<bool>(n+1);
    int x,y;
    for(int i = 1; i <= m; ++i)
    {
        is >> x >> y;
        g[x].push_back(y);
        g[y].push_back(x);

    }
}

int Df(int x)
{
    v[x] = true;
    for(vector<int> :: iterator it = g[x].begin(); it != g[x].end(); ++it)
    {
        if(!v[*it])
            Df(*it);
    }

}