#include <stdio.h>
#include <algorithm>
#include <vector>
#define nmax 100000

using namespace std;

vector <int> g[nmax];
int x,y,n,m,viz[nmax],nc;

void df (int nod)
{
    int i;
    viz[nod]=1;
    for(i=0;i<g[nod].size ();++i)
        if(!viz[g[nod][i]]) df(g[nod][i]);
}

int main ()
{
    int i;
    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);
        g[x].push_back (y);
        g[y].push_back (x);
    }
    for(i=1;i<=n;i++)
    {
        if(!viz[i])
        {
            df(i);
            nc++;
        }
    }
    printf("%d", nc);
    return 0;
}