#include <iostream>
#include <fstream>
#include <vector>
#define nmax 100005

using namespace std;

vector <int> G[nmax];
int viz[nmax],comp[nmax];

void dfs(int nod, int nr){
    int it,y;
    viz[nod]=1;
    comp[nod]=nr;
    for(it=0;it<G[nod].size();it++){
        y=G[nod][it];
        if(!viz[y])
            dfs(y,nr);
    }
}

int main()
{
    int i,n,m,nr,x,y;
    ifstream f("dfs.in");
    ofstream g("dfs.out");
    nr=0;
    f >> n >> m;
    for (i=1;i<=m;i++){
        f >> x >> y;
        G[x].push_back(y);
        G[y].push_back(x);
    }
    for (i=1;i<=n;i++){
        if (!viz[i]){
            nr++;
            dfs(i,nr);
        }
    }
    g << nr;
}