#include <algorithm>
#include <cstdio>
#include <vector>

using namespace std;

int N, M, ans = 0;
vector<bool> visited;
vector<vector<int>> G;

void dfs(int node) {
    visited[node] = true;
    for (auto neigh : G[node]) {
        if (!visited[neigh])
            dfs(neigh);
    }
}

int main() {
    freopen("dfs.in", "r", stdin);
    freopen("dfs.out", "w", stdout);

    scanf("%d %d", &N, &M);

    G.resize(N + 1);       // G devine un vector de dimensiune N + 1
    visited.resize(N + 1); // visited e vector de N + 1 elemente
    fill(visited.begin(), visited.end(),
         false); // toate nodurile sunt nevizitate (false)

    for (int i = 1; i <= M; i++) {
        int x, y;
        scanf("%d %d", &x, &y);
        G[x].push_back(y);
        G[y].push_back(x);
    }

    for (int i = 1; i <= N; i++) {
        if (!visited[i]) {
            dfs(i);
            ans++;
        }
    }

    printf("%d\n", ans);

    return 0;
}