#include <iostream>
#include <fstream>
#include <vector>

using namespace std;

ifstream fin("dfs.in");
ofstream fout("dfs.out");

vector <int> v[100005];
bool viz[100005];
int m,x;

void dfs(int nod){
    for(int i=0;i<v[nod].size();i++){
        if(!viz[v[nod][i]]){
            viz[v[nod][i]]=1;
            dfs(v[nod][i]);
        }
    }
}

int i,y;
int n,much;

int main()
{
    fin>>n>>much;
    for(i=1;i<=much;i++){
        fin>>x>>y;
        v[x].push_back(y);
        v[y].push_back(x);
    }
    x=0;
    for(i=1;i<=n;i++){
        if(!viz[i]){
            dfs(i);
            x++;
        }
    }
    fout<<x<<'\n';
    return 0;
}