#include <fstream>
#include <vector>
#define dim 100010
using namespace std;
vector <int> a[dim];
int f[dim];
int i,n,m,nr,x,y;

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

int main() {
    ifstream fin("dfs.in");
    ofstream fout("dfs.out");
    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]==0) {
            nr++;
            dfs(i);
        }
    }
    fout<<nr;
    return 0;
}