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