#include <cstdio>
#include <cstring>
#include <ctime>
#include <cstdlib>
#include <cmath>
#include <algorithm>
#include <vector>
#include <queue>

using namespace std;

struct nod
{
    int x;
    nod *u;
};
typedef nod *pnod;
pnod v[100005];

int n, m, x, y, t, i, viz[100005];

void A(pnod &d, int x)
{
    pnod p;
    p = new nod;
    p->x=x;
    p->u=d;
    d=p;
}

void DFS(int x)
{
    viz[x]=1;
    for(pnod p=v[x];p!=0;p=p->u)
        if(!viz[p->x])
            DFS(p->x);
}

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(v[x], y);
        A(v[y], x);
    }
    for(i=1;i<=n;i++)
        if(!viz[i])
        {
            t++;
            DFS(i);
        }
    printf("%d", t);
    return 0;
}