#include <bits/stdc++.h>

using namespace std;

struct node {
    int n;
    node *next;
};

void add_node(node **dest, int n)
{
    node *new_node = new node;
    new_node->n = n;
    new_node->next = *dest;
    *dest = new_node;
}

void DFS(int i, vector<bool> &visited, vector<node*> nodes)
{
    visited[i] = 1;
    for (node *p = nodes[i]; p != nullptr; p = p->next) {
        if (!visited[p->n]) {
            DFS(p->n, visited, nodes);
        }
    }
}

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

    int n, m;
    cin >> n >> m;

    vector<node*> nodes(n);
    for (int i = 0; i < n; i++) {
        nodes[i] = new node;
        nodes[i]->next = nullptr;
    }

    for (int i = 0, x, y; i < m; i++) {
        cin >> x >> y;
        add_node(&nodes[x], y);
        add_node(&nodes[y], x);
    }

    vector<bool> visited(n);
    for (int i = 0; i < n; i++) visited[i] = 0;

    int solution = 0;
    for (int i = 0; i < n; i++) {
        if (!visited[i]) {
            solution++;
            DFS(i, visited, nodes);
        }
    }
    cout << solution << "\n";

    return 0;
}