#include <cstdio>
#include <bitset>
#include <vector>
#define NMAX 100005
using namespace std;
vector <int> v[NMAX];
bitset <NMAX> viz;
int N,M,i,x,y,NR;
void DFS(int nod)
{
    viz[nod]=1;
    vector <int> ::iterator i;
    for (i=v[nod].begin();i!=v[nod].end();i++)
        if (!viz[*i]) DFS(*i);
}
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);
        v[x].push_back(y);
        v[y].push_back(x);
    }
    for (i=1;i<=N;i++)
        if (!viz[i]) ++NR,DFS(i);
    printf("%d",NR);
}