#include <fstream>
#include <vector>

using namespace std;

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

const int MAX_N = 100005;

vector <int> G[MAX_N];
int n, m, X, Y;
bool marked[MAX_N];

void Read()
{
    cin >> n >> m;
    for (int i = 1; i <= m; ++i) {
        cin >> X >> Y;
        G[X].push_back(Y);
        G[Y].push_back(X);
    }
}

void DFS(int node)
{
    vector<int>::iterator it;
    marked[node] = true;

    for (it = G[node].begin(); it != G[node].end(); ++it)
        if (!marked[*it])
            DFS(*it);
}

void Solve()
{
    int res = 0;
    for (int i = 1; i <= n; ++i)
        if (!marked[i]) {
            res++;
            DFS(i);
        }
    cout << res;
}

int main()
{
    Read();
    Solve();

    cin.close();
    cout.close();

    return 0;
}