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

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

bool v[100001];
vector<vector<int> > G;
int nrc, n, m;

void Df(int node);
void Read();


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

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

void Df(int node)
{
    v[node] = true;
    for ( const auto& g : G[node] )
        if ( !v[g] )
            Df(g);
}

void Read()
{
    is >> n >> m;
    G = vector<vector<int> >(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);
    }
}