#include <cstdio>
#include <vector>

#define Nmax 100005

using namespace std;

int N, M, Viz[Nmax], Sol;
vector <int> G[Nmax];

void Citire()
{
    int a, b;
    scanf("%d %d", &N, &M);
    for (int i = 1; i <= M; ++i)
    {
        scanf("%d %d", &a, &b);
        G[a].push_back(b);
        G[b].push_back(a);
    }
}

void DFS(int nod)
{
    vector <int> :: iterator it;
    Viz[nod] = 1;
    for (it = G[nod].begin(); it != G[nod].end(); ++it)
        if (!Viz[*it])
            DFS(*it);
}

void Afisare()
{
    printf("%d", Sol);
}

int main()
{
    freopen("dfs.in", "r", stdin);
    freopen("dfs.out", "w", stdout);

    Citire();
    for (int i = 1; i <= N; ++i)
        if (!Viz[i])
        {
            DFS(i);
            Sol++;
        }
    Afisare();

    return 0;
}