#include <iostream>
#include <fstream>
#include <vector>
using namespace std;
const int dim=1e5+5;
int n,m,nr;
bool viz[dim];
vector<int> G[dim];
void dfs(int nod){
    viz[nod]=1;
    for(auto x:G[nod]){
        if(!viz[x]){
            dfs(x);
        }
    }
}
int main(){
    ifstream f("dfs.in");
    ofstream g("dfs.out");
    f>>n>>m;
    for(int i=1;i<=m;i++){
        int x,y;
        f>>x>>y;
        G[x].push_back(y);
        G[y].push_back(x);
    }
    for(int i=1;i<=n;i++){
        if(!viz[i]){
            nr++;
            dfs(i);
        }
    }
    g<<nr;
    return 0;
}