#include<stdio.h>
using namespace std;

typedef struct lista
            {
                int info;
                lista*next;
            }*nod;
nod a[100002];
bool viz[100004];
int i,j,x,y,m,n,k;

void add(int x, nod &p)
{
    nod r= new lista;
    r->info=x;
    r->next=p;
    p=r;
}

void dfs(int x)
{
    nod r=a[x];
    viz[x]=1;
    while (r)
    {
        if (viz[r->info]==0) dfs(r->info);
        r=r->next;
    }
}

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);
        add(x,a[y]);
        add(y,a[x]);
    }
    for (i=1; i<=n ; ++i)
    if (viz[i]==0)
            {
                k++;
                dfs(i);
            }
    printf("%d",k);
    return 0;
}