#include <iostream>
#include <fstream>
#include <vector>
#define Nmax 100010
using namespace std;
ifstream f("dfs.in");
ofstream g("dfs.out");
vector <int> adj[Nmax];
int vis[Nmax],n,m,connex;

void dfs(int v)
{

    vis[v]=1;
    for(int i=0;i<adj[v].size();i++)
    {
        int w=adj[v][i];
        if(!vis[w])
            dfs(w);
    }
}

int main()
{
    f >> n >> m;
    int x,y;
    for(int i=0;i<m;i++)
    {
        f >> x >> y;
        adj[x].push_back(y);
        adj[y].push_back(x);
    }
    for(int i=1;i<=n;i++)
    {
        if(!vis[i])
        {
            dfs(i);
            connex++;
        }
    }
    g << connex;
    return 0;
}