#include<bits/stdc++.h>
using namespace std;
const int N=50005;
int n,m,fa[N];
int find(int x){
    return fa[x]==x?x:fa[x]=find(fa[x]);
} 
int main(){
    freopen("religion.in","r",stdin);
    freopen("religion.out","w",stdout);
    scanf("%d%d",&n,&m);
    for(int i = 1;i<=n;i++) fa[i]=i;
    while(m--){
        int x,y; scanf("%d%d",&x,&y);
        int fx=find(x),fy=find(y);
        if(fx!=fy) fa[fx]=fy;
    }
    int ans=0;
    for(int i = 1;i<=n;i++) 
    if(fa[i]==i) ans++;
    printf("%d",ans);
    return 0;
}