#include <cstdio>
#include <vector>

using namespace std;

void read(int &n, int &m, vector<vector<int> > &graph) {
    int left_node, right_node;

    scanf("%d %d", &n, &m);

    for (int i = 0; i < n; i++) {
        graph.push_back(vector<int>());
    }

    for (int i = 0; i < m; i++) {
        scanf("%d %d", &left_node, &right_node);
        graph[left_node - 1].push_back(right_node - 1);
        graph[right_node - 1].push_back(left_node - 1);
    }
}

void dfs(vector<vector<int> > graph, vector<bool> &flag, int start_node) {
    flag[start_node] = true;

    for (vector<int>::iterator it = graph[start_node].begin(); it != graph[start_node].end(); it++) {
        if (!flag[*it]) {
            dfs(graph, flag, *it);
        }
    }
}

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

    int n, m;
    int connected_components = 0;
    vector<vector<int> > graph;

    read(n, m, graph);

    vector<bool> flag(n, false);
    for (int i = 0; i < n; i++) {
        if (!flag[i]) {
            dfs(graph, flag, i);
            connected_components++;
        }
    }

    printf("%d", connected_components);

    return 0;
}