#include <fstream>
#include <vector>
using namespace std;
ifstream cin ("dfs.in");
ofstream cout ("dfs.out");
vector <int> lista[100010];
int viz[100010];
void dfs(int nod)
{
    int i;
    viz[nod]=1;
    for (i=0; i<lista[nod].size(); i++)
        if (viz[lista[nod][i]]==0)
            dfs(lista[nod][i]);
}
int main()
{
    int n,m,i,ct,x,y;
    cin>>n>>m;
    for (i=1; i<=m; i++)
    {
        cin>>x>>y;
        lista[x].push_back(y);
        lista[y].push_back(x);
    }
    ct=0;
    for (i=1; i<=n; i++)
        if (viz[i]==0)
        {
            dfs(i);
            ct++;
        }
    cout<<ct;
    return 0;
}