#include <bits/stdc++.h>

using namespace std;

ifstream fin("dfs.in");
ofstream fout("dfs.out");

const int N_MAX = 1e5 + 5;

int N, M;
int x, y;

vector < int > G[N_MAX];

int vis[N_MAX];
void DFS(int currNode)
{
    vis[currNode] = 1;
    int node;
    for (int i = 0; i < G[currNode].size(); i++) {
        node = G[currNode][i];
        if (vis[node] == 0) {
            DFS(node);
        }
    }
}

int main()
{
    fin >> N >> M;
    for (int i = 1; i <= M; i++) {
        fin >> x >> y;
        G[x].push_back(y);
        G[y].push_back(x);
    }

    int sol = 0;
    for (int i = 1; i <= N; i++) {
        if (vis[i] == 0) {
            DFS(i);
            sol++;
        }
    }
    fout << sol << "\n";
    return 0;
}