#include <cstdio>
#include <vector>

using namespace std;

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

void dfs(int nod)
{
    vector <int>::iterator it;
    viz[nod]=1;
    for(it=a[nod].begin(); it!=a[nod].end(); ++it)
    if(!viz[*it]) dfs(*it);

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

    scanf("%d%d", &n, &m);
    for(i=1; i<=m; ++i)
    {
        scanf("%d%d", &x, &y);
        a[x].push_back(y);
        a[y].push_back(x);
    }
    for(i=1; i<=n; ++i)
    if(!viz[i])
    {
        conexe++;
        dfs(i);
    }

    printf("%d", conexe);

    return 0;
}