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

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

using VI = vector<int>;
using VB = vector<bool>;

int n, m, cnt;
vector<VI> G;
VB v;

void Read();
void Dfs(int x);

int main()
{
    Read();
    for (int i = 1; i <= n; i++)
        if ( !v[i] )
        {
            cnt++;
            Dfs(i);
        }
    fout << cnt;

    fin.close();
    fout.close();
}

void Dfs(int x)
{
    v[x] = true;
    for (const int& y : G[x])
        if ( !v[y] )
            Dfs(y);
}

void Read()
{
    fin >> n >> m;
    G = vector<VI>(n + 1);
    v = VB(n + 1);

    int x, y;
    for (int i = 1; i <= m; i++)
    {
        fin >> x >> y;
        G[x].push_back(y);
        G[y].push_back(x);
    }
}