#include <stdio.h>

typedef struct noduri
{
    int val;
    noduri *urm;
} adr;

adr *L[100000],*p;
int n,m,i,j,k,kont;
short int E[100000];

void df(int nod)
{
    adr *p;
    E[nod]=1;
    p=L[nod];
    while (p)
    {
        if (!E[p->val]) df(p->val);
        p=p->urm;
    }
}

int main()
{
    freopen("dfs.in","r",stdin);
    freopen("dfs.out","w",stdout);
    scanf("%d %d\n",&n,&m);
    for (k=1; k<=m; k++)
    {
        scanf("%d %d",&i,&j);
        p=new adr;
        p->val=j; p->urm=L[i];
        L[i]=p;
        p=new adr;
        p->val=i; p->urm=L[j];
        L[j]=p;
    }
    kont=0;
    for (i=1; i<=n; i++)
        if (!E[i])
        {
            kont++;
            df(i);
        }
    printf("%d",kont);
    return 0;
}