#include <fstream>
#include <vector>

using namespace std;

#define MAXN 100005

ifstream cin("dfs.in");
ofstream cout("dfs.out");

vector<int> g[MAXN];

bool ok[MAXN];

void DFS(int Nod)
{
    ok[Nod] = 1;

    for(int i = 0; i < g[Nod].size(); i++)
    {
        int Vecin = g[Nod][i];

        if(!ok[Vecin])
            DFS(Vecin);
    }
}

int main()
{
    int n, m;
    cin >> n >> m;
    int x, y;
    int r = 0;

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

    for(int i = 1; i <= n; i++)
    {
        if(!ok[i])
        {
            r++;
            DFS(i);
        }
    }

    cout << r;
}