#include<fstream>
#include<vector>
using namespace std;
int v[100003], i, n, m, x, y, sol;
vector <int> L[100003];
ifstream in("dfs.in");
ofstream out("dfs.out");
void dfs(int nod){
    v[nod]=1;
    int i=0;
    for(i=0; i<L[nod].size(); i++){
        if(v[L[nod][i]]==0)
            dfs(L[nod][i]);
    }
    return;
}
int main(){
    in>>n>>m;
    for(i=1; i<=m; i++){
        in>>x>>y;
        L[x].push_back(y);
        L[y].push_back(x);
    }
    for(i=1; i<=n; i++){
        if(v[i]==0){
            sol++;
            dfs(i);
        }
    }
    out<<sol;
}