#include <iostream>
#include <vector>
#include <fstream>
using namespace std;

vector <int> a[100001];
bool viz[100001];
int m,n,i;

void dfs(int ns)
{
    viz[ns]=1;
    for(unsigned i=0;i<a[ns].size();i++)
    {
        if(viz[a[ns][i]]==0) dfs(a[ns][i]);
    }
}

int main()
{
	ifstream in("dfs.in");
	ofstream out("dfs.out");
    int x,y,j,nrc=0;
    /*c*/in >> n >> m;
    for(i=0;i<m;i++)
    {
        /*c*/in >> x >> y;
        a[x].push_back(y);
        a[y].push_back(x);
    }
    
    for(i=1;i<=n;i++)
    {
        if(viz[i]==0)
        {
            dfs(i);
            nrc++;
        }
    }
    
    /*c*/out << nrc;
    return 0;
}