#include <fstream>
#include <vector>

using namespace std;

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

vector < int > v[100005];

bool used[100005];

int n , m , cnt;

void dfs(int k)
{
    used[k] = true;

    for(auto i : v[k])
    {
        if(used[i] == false)
            dfs(i);
    }
}

int main()
{
    f >> n >> m;

    for ( int i = 1 ; i <= m ; i++)
    {
        int x , y;
        f >> x >> y;
        v[x] . push_back(y);
        v[y] . push_back(x);
    }

    for ( int i = 1 ; i <= n ; i++)
    {
        if(used[i] == false)
        {
            dfs(i);
            cnt++;
        }
    }

    g << cnt;

    return 0;
}