#include <bits/stdc++.h>
using namespace std;
ifstream ci("dfs.in");
ofstream cou("dfs.out");

vector<int>v[100005];
bool vis[100000];
int n,m;
void citire(){
    int a,b;
    ci>>n>>m;
    for(int i=1;i<=m;i++){
        ci>>a>>b;
        v[a].push_back(b);
        v[b].push_back(a);
    }

}



void Dfs(int a){

    vis[a]=1;
    for(auto i:v[a] ){
        if(vis[i]==0){
            Dfs(i);
        }
    }

}

void rez(){
    int i,cn=0;
    for(i=1;i<=n;i++){
        if(vis[i]==0 ){
            cn++;
            Dfs(i);
        }
    }
    cou<<cn;


}


int main()
{
    citire();
    rez();
    return 0;
}