#include<cstdio>
#include<vector>
#define maxn 100005
using namespace std;
int viz[maxn],n,m,nrr,x,y;
vector <int> G[maxn];
void dfs(int nod){
    viz[nod]=1;
    for(int i=0;i<G[nod].size();++i){
        if(!viz[G[nod][i]]){
            dfs(G[nod][i]);
        }
    }
}
int main(){
    freopen("dfs.in","r",stdin);
    freopen("dfs.out","w",stdout);
    scanf("%d%d",&n,&m);

    for(int i=1;i<=m;++i){
        scanf("%d%d",&x,&y);
        G[x].push_back(y);
        G[y].push_back(x);
    }
    for(int i=1;i<=n;++i)
        if(!viz[i]){
            ++nrr;
            dfs(i);
        }
    printf("%d",nrr);
    return 0;

}