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