#include <bits/stdc++.h>

using namespace std;

int n, m;
vector<vector<int>> adj;
vector<int> viz;

void DFS(int i)
{
    viz[i]=1;

    for(int j = 0; j < adj[i].size(); j++)
    {
        if (!viz[adj[i][j]])
            DFS(adj[i][j]);
    }
}

int main()
{
    ifstream fin("dfs.in");
    ofstream fout("dfs.out");
    fin >> n >> m;
    adj.resize(n + 5);
    viz.resize(n + 5);

    for (int i = 1; i <= m; i++)
    {
        int x, y;
        fin >> x >> y;

        adj[x].push_back(y);
        adj[y].push_back(x);
    }

    int count = 0;
    for(int i = 1; i <= n; i++)
    {
        if (!viz[i])
        {
            DFS(i);
            count++;
        }
    }

    fout << count;

    return 0;
}