#include<cstdio>
#include<vector>
#include<algorithm>
using namespace std;
vector <int>v[100005];
bool viz[100005];
void dfs(int nod)
{
    int i,len;
    len=(int)v[nod].size();
    viz[nod]=1;
    for(i=0;i<=len;i++)
        if(!viz[v[nod][i]])
    dfs(v[nod][i]);
}
int main(){
    int n,m,i,a,b,tot;
    freopen("dfs.in","r",stdin);
    freopen("dfs.out","w",stdout);
    scanf("%d%d",&n,&m);
    for(i=1;i<=m;i++)
    {
        scanf("%d%d",&a,&b);

         v[a].push_back(b);
         v[b].push_back(a);
    }
    tot=0;
    for(i=1;i<=n;i++){
        if(!viz[i])
        {
            tot++;
            dfs(i);
        }
    }
    printf("%d",tot);
    return 0;
}