#include <fstream>
#include <vector>
using namespace std;
ifstream cin("dfs.in");
ofstream cout("dfs.out");
vector <int> a[100001];
int n, m, x, y, i, j, l;
bool use[100001];
void dfs(int nod)
{
    if (use[nod] = 1)
        for (auto i : a[nod])
            if (use[i] == 0)
                dfs(i);
}
int main()
{
    cin >> n >> m;
    for (i = 1;i <= m;i++)
    {
        cin >> x >> y;
        a[x].push_back(y);
        a[y].push_back(x);
    }
    for (i = 1;i <= n;i++)
    {
        if (use[i] == 0)
        {
            l++;
            dfs(i);
        }
    }
    cout << l;
}