#include <iostream>
#include <vector>
#include <fstream>

using namespace std;

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

vector <int> mu[100005];
int vis[100005];

void dfs(int nod){
    vis[nod]=1;
    for(int i=0;i<mu[nod].size();i++)
        if(vis[mu[nod][i]]==0)
            dfs(mu[nod][i]);
}

int main()
{
    int n,m,nrcomp=0,a,b;
    in>>n>>m;
    for(int i=1;i<=m;i++){
        in>>a>>b;
        mu[a].push_back(b);
        mu[b].push_back(a);
    }
    for(int i=1;i<=n;i++)
        if(vis[i]==0)
        {
            dfs(i);
            ++nrcomp;
        }
    out<<nrcomp;
    return 0;
}