#include <fstream>
#include<vector>
using namespace std;
ifstream f("dfs.in");
ofstream g("dfs.out");
int i,n,m,viz[100001],x,y;
vector <int>a[100001];
void df(int k){
    viz[k]=1;
    for ( int i=0;i<a[k].size();i++)
        if (viz[a[k][i]]==0)
            df(a[k][i]);
}
int main(){
    f>>n>>m;
    for (i=1;i<=m;i++){
        f>>x>>y;
        a[x].push_back(y);
        a[y].push_back(x);
    }
    int nr=0;
    for (int i=1;i<=n;i++)
        if (viz[i]==0){
            nr++;
            df(i);
    }
    g<<nr;
    return 0;
}