#include <fstream>
#include <vector>

using namespace std;

ifstream cin("dfs.in");
ofstream cout("dfs.out");

const int N=100001;

vector <int> a[N];
int n,m,viz[N],s;

void citire()
{
    cin >> n >> m;
    int i,x,y;
    for(i=0; i<m; i++)
    {
        cin >> x >> y;
        a[x].push_back(y);
        a[y].push_back(x);
    }
    cin.close();
}

void dfs(int x)
{
    viz[x] = true;
    int i,y;
    for(i=0; i<a[x].size(); i++)
    {
        y=a[x][i];
        if(!viz[y])
        {
            dfs(y);
        }
    }
}

int main()
{
    citire();
    int i;
    for(i=1; i<=n; i++)
        if(!viz[i])
        {
            dfs(i);
            s++;
        }
    cout << s;
    return 0;
}