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

using namespace std;

ifstream f ("dfs.in");
ofstream g ("dfs.out");

const int N=100001;
vector<int> a[N];
int n, m, c;
bool viz[N];

void citire ();
void dfs (int x);

int main()
{
    citire();
    for (int i=0; i<n; i++)
    {
        if (viz[i]==false)
        {
            c++;
            dfs(i);
        }
    }
    g<<c;
    return 0;
}

void citire()
{
    f>>n>>m;
    int x, y;
    for (int i=0; i<m; i++)
    {
        f>>x>>y;
        a[x].push_back(y);
        a[y].push_back(x);
    }
    f.close();
}

void dfs(int x)
{
    viz[x]=true;
    int s=a[x].size();
    for (int i=0; i<s; i++)
    {
        int y=a[x][i];
        if (!viz[y])
        {
            dfs(y);
        }
    }
}