#include <fstream>
#include <vector>
#define N 100005

using namespace std;
ifstream fin("bfs.in");
ofstream fout("bfs.out");

vector <int> muchii[N];
int n, m, viz[N], ct;

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

    }
}

void DFS(int x)
{
    int i;
    viz[x] = 1;
    for (auto i : muchii[x])
        if (viz[i] == 0)
            DFS(i);
}

void Rezolvare()
{
    int i;
    for (i = 1; i <= n; i++)
    {
        if (viz[i] == 0)
        {
            ct++;
            DFS(i);
        }
    }
    fout << ct;
}


int main()
{
    Citire();
    Rezolvare();
    return 0;
}