#include <fstream>
#include <vector>
#include <stack>
#define MAXN 100001
using namespace std;
ifstream f("dfs.in");
ofstream g("dfs.out");

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

void read() {
    int node1, node2;
    f >> N >> M;
    for (int i = 1; i <= M; ++i) {
        f >> node1 >> node2;
        G[node1].push_back(node2);
        G[node2].push_back(node1);
    }
}
void dfs(int node) {
    stack<int> S;
    int current;

    viz[node] = true;
    S.push(node);
    while (!S.empty()) {
        current = S.top();
        S.pop();
        for (auto it = G[current].begin(); it != G[current].end(); ++it) {
            if (viz[*it] == false) {
                S.push(*it);
                viz[*it] = true;
            }
        }
        /*
        In loc de iteratori:

        for (int i = 0; i < G[current].size(); ++i) {
            int next = G[node][i];
            if (viz[next] == false) {
                S.push(next);
                viz[next] = true;
            }
        }
        */
    }
}
int main()
{
    int answer = 0;
    read();
    for (int node = 1; node <= N; ++node) {
        if (viz[node] == false) {
            ++answer;
            dfs(node);
        }
    }
    g << answer;
    return 0;
}