#include <fstream>
#include <vector>

using namespace std;

const int NMAX=100005;
int v[NMAX];
bool f[NMAX];

vector <int> a[NMAX];

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

void dfs(int nod){
    int i,x=a[nod].size();
    for(i=0;i<x;i++){
        if(!f[a[nod][i]]){
            f[a[nod][i]]=1;
            dfs(a[nod][i]);
        }
    }
}

int main()
{
    int n,m,i,x,y,nr=0;
    fin>>n>>m;
    for(i=1;i<=m;i++){
        fin>>x>>y;
        a[x].push_back(y);
        a[y].push_back(x);
    }
    for(i=1;i<=n;i++){
        if(!f[i]){
            dfs(i);
            nr++;
        }
    }
    fout<<nr<<"\n";
    return 0;
}