#include <stdio.h>
#include <vector>
#define lim 100005
using namespace std;
vector <int> v[lim];
int viz[lim];
void dfs(int nod){
    int i,n=v[nod].size();
    viz[nod]=1;
    for(i=0;i<n;i++)
        if(viz[v[nod][i]]==0)
            dfs(v[nod][i]);
}
int main(){
    FILE *fin,*fout;
    fin=fopen("dfs.in","r");
    fout=fopen("dfs.out","w");
    int i,n,m,x,y,cate=0;
    fscanf(fin,"%d%d",&n,&m);
    for(i=1;i<=m;i++){
        fscanf(fin,"%d%d",&x,&y);
        v[x].push_back(y);
        v[y].push_back(x);
    }
    for(i=1;i<=n;i++)
        if(viz[i]==0){
            cate++;
            dfs(i);
        }
    fprintf(fout,"%d",cate);
    fclose(fin);
    fclose(fout);
    return 0;
}