#include <iostream>
#include <fstream>
#include <algorithm>
#include <vector>
#include <queue>
#include <bitset>

using namespace std;

ifstream fin ("dfs.in");
ofstream fout("dfs.out");
#define MAX 100100

vector <int> G[MAX];
bitset <MAX> viz;
queue <int> coada;

int main()
{
    int n, m, i, j, a, b, x, k;
    fin>>n;
    fin>>m;
    for(i=1;i<=m;i++)
    {
        fin>>a>>b;
        G[a].push_back(b);
        G[b].push_back(a);
    }
    k=0;
    for(i=1;i<=n;i++)
    {
        if(!viz[i])
        {
            k++;
            coada.push(i);
            viz[i]=1;
            while(!coada.empty())
            {
                x=coada.front();
                coada.pop();
                for(j=0;j<G[x].size();j++)
                {
                    if(!viz[G[x][j]])
                    {
                        viz[G[x][j]]=1;
                        coada.push(G[x][j]);
                    }
                }
            }
        }
    }
    fout<<k<<"\n";



    return 0;
}