#include <stdio.h>
#include <map>
#include <list>

using namespace std;

int n, m, x, y;
map<int, list<int>> adj;
map<int, bool> visited;
FILE *in, *out;

void dfs(int start) {
    if (!visited[start]) visited[start] = true;

    for (auto neigh : adj[start])
        if (!visited[neigh]) {
            visited[neigh] = true;
            dfs(neigh);
        }
}

int main() {
    int rez = 0;
    in = fopen("dfs.in", "r");
    out = fopen("dfs.out", "w");

    fscanf(in, "%d %d", &n, &m);

    // create adjacency lists
    for (int i = 0; i < m; i++) {
        fscanf(in, "%d %d", &x, &y);
        adj[x].push_back(y);
        adj[y].push_back(x);
    }

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

    fprintf(out, "%d", rez);

    fclose(in);
    fclose(out);

    return 0;
}