#include <iostream>
#include <fstream>
#include <vector>
using namespace std;
ifstream fin("dfs.in");
ofstream fout("dfs.out");
#define MAX 100010
vector <int> G[MAX];
int viz[MAX];

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

int main()
{
    int n, m, a, b;
    fin>>n>>m;
    while(m--)
    {
        fin>>a>>b;
        G[a].push_back(b);
        G[b].push_back(a);
    }
    int k=0;
    for(int i=1;i<=n;i++)
    {
        if(!viz[i])
            dfs(i), k++;
    }
    fout<<k;
}