#include <iostream>
#include <vector>

#define NMax 100005

using namespace std;

vector <int> G[NMax];
int N, Viz[NMax], NC;

void Read ()
{
    freopen ("dfs.in", "r", stdin);
    int M;
    scanf ("%d %d", &N, &M);
    for (; M>0; --M)
    {
        int X, Y;
        scanf ("%d %d", &X, &Y);
        G[X].push_back (Y);
        G[Y].push_back (X);
    }
}

void Print ()
{
    freopen ("dfs.out", "w", stdout);
    printf ("%d\n", NC);
}

void DFS (int X)
{
    Viz[X]=true;
    for (unsigned i=0; i<G[X].size (); ++i)
    {
        int V=G[X][i];
        if (!Viz[V])
        {
            DFS (V);
        }
    }
}

int main()
{
    Read ();
    for (int i=1; i<=N; ++i)
    {
        if (!Viz[i])
        {
            ++NC;
            DFS (i);
        }
    }
    Print ();
    return 0;
}