//#include <iostream>
#include <fstream>
#include<vector>
#include<string>
#include<queue>
#include<algorithm>
#define inf 1000000000

using namespace std;
ifstream cin("dfs.in");
ofstream cout("dfs.out");

int i,j,n,m,x,y,nr;
bool b[100001];
vector<int> v[100001];
queue<int> q;

int main(){
    cin>>n>>m;
    for(i=1;i<=m;i++){
        cin>>x>>y;
        v[x].push_back(y);
        v[y].push_back(x);
    }

    for(i=1;i<=n;i++){
        if(!b[i]){
            nr++;
            q.push(i);
            while(!q.empty()){
                x=q.front();
                q.pop();
                b[x]=1;
                for(j=0;j<v[x].size();j++){
                    if(!b[v[x][j]]){
                        q.push(v[x][j]);
                        b[v[x][j]]=1;
                    }
                }
            }
        }
    }
    cout<<nr;    return 0;
}