#include <fstream>
#include <vector>
using namespace std;
ifstream fin("dfs.in");
ofstream fout("dfs.out");
int v[100001],x,y,n,m,i,nr;
vector <int> L[100010];
void dfs(int nod){
    int i;
    v[nod]=1;
    for (i=0;i<L[nod].size();i++) {
        int vecin=L[nod][i];
        if (v[vecin]==0)
            dfs(vecin);
    }
}
int main()
{
    fin>>n>>m;
    for (i=1;i<=m;i++){
        fin>>x>>y;
        L[x].push_back(y);
        L[y].push_back(x);
    }
    for (i=1;i<=n;i++)
        if (v[i]==0)
        {
            dfs(i);
            nr++;
        }
    fout<<nr;
    return 0;
}