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