#include <fstream>
#include <vector>
using namespace std;

vector<int>graph[100005];

ifstream f("dfs.in");
ofstream g("dfs.out");

int n, m, x, y;
int viz[100005];
int nr;

void dfs(int i){
    for(auto &v:graph[i])
        if(viz[v]==0){
            viz[v]=1;
            dfs(v);
        }
}

void citire(){
    f>>n>>m;
    for(int i=1; i<=m; i++){
        f>>x>>y;
        graph[x].push_back(y);
        graph[y].push_back(x);
    }
}

int main(){
    citire();
    for(int i=1; i<=n; i++)
        if(viz[i]==0){
            viz[i]=1;
            dfs(i);
            nr++;
        }
    g<<nr;
    return 0;
}