#include <fstream>
#include <vector>
using namespace std;

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

const int MAXN = 100005;

int N, M, Sol;
bool marked[MAXN];
vector<int> G[MAXN];

void Read() {
    fin >> N >> M;
    int a, b;
    for (int i = 0; i < M; ++i) {
        fin >> a >> b;
        G[a].push_back(b);
        G[b].push_back(a);
    }
}

void DFS(int node) {
    marked[node] = true;
    vector<int>::iterator it;
    for (it = G[node].begin(); it != G[node].end(); ++it)
        if (!marked[*it])
            DFS(*it);
}

int main() {
    Read();
    for (int i = 1; i <= N; ++i) {
        if (!marked[i]) {
            ++Sol;
            DFS(i);
        }
    }
    fout << Sol << '\n';
    fin.close();
    fout.close();
    return 0;
}