//dfs
#include <iostream>
#include <vector>
#include <fstream>
using namespace std;
ifstream fin("dfs.in");
ofstream fout("dfs.out");
const int MAXN=100000;
vector<int> adj[MAXN + 1];
bool vizitat[MAXN + 1];
void dfs(int node)
{
    vizitat[node]=true;
    for (int i=0; i<(int)adj[node].size();i++)
    {
        int v = adj[node][i];
        if (!vizitat[v]) dfs(v);
    }
}
int main()
{
    int n, m;
    fin >> n >> m;
    for (int i = 0; i < m; i++)
    {
        int x, y;
        fin >> x >> y;
        adj[x].push_back(y);
        adj[y].push_back(x);
    }
    int comp = 0;
    for (int i = 1; i <= n; i++)
    {
        if (!vizitat[i])
        {
            dfs(i);
            comp++;
        }
    }
    fout<<comp<<"\n";
    return 0;
}