#include<stdio.h>
#include<vector>
using namespace std;
vector<int>v[100001];
int viz[100001];
void dfs ( int nod ){
    int i;
    viz[nod]=1;
    for(i=0;i<v[nod].size();i++)
        if(viz[v[nod][i]]==0)
            dfs(v[nod][i]);
}
int main(){
    int a,b,n,m,i,cate;
    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);
    }
    cate=0;
    for(i=1;i<=n;i++)
        if(viz[i]==0){
            dfs(i);
            cate++;
    }
    printf("%d\n",cate);
    return 0;
}