#include <fstream>
#include <vector>
#define NMAX 100004

using namespace std;

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

vector <int> G[NMAX];
bool uz[NMAX];

int n, m, nrc;

void DFS(int x);
void citire();

int main()
{
    int i, j;
    citire();

    for(i = 1; i <= n; ++i)
    {
        if(!uz[i])
        {
            nrc++;
            DFS(i);
        }
    }
    fout << nrc << '\n';
    return 0;
}

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

void DFS(int x)
{
    int i;
    uz[x] = true;
    for(i = 0; i < G[x].size(); ++i)
    {
        if(!uz[G[x][i]])
        {
            DFS(G[x][i]);
        }
    }
}