#include <iostream>
#include<cstdio>
#include<vector>
#define Nmax 100001
using namespace std;
vector <int> G[Nmax];
int N,M,Nc;
bool Use[Nmax];
void DFS(int Nod)
{
    vector<int>:: iterator it;
    Use[Nod]=1;
    for(it=G[Nod].begin();it!=G[Nod].end();it++)
        if(!Use[*it])
            DFS(*it);

}
int main()
{
    int i,x,y;
    freopen("dfs.in","r",stdin);
    freopen("dfs.out","w",stdout);
    scanf("%d %d",&N,&M);
     for(i=0;i<M;i++)
    {
        scanf("%d %d",&x,&y);
        G[x].push_back(y);
        G[y].push_back(x);
    }
   for(i=1;i<=N;i++)
   {
       if(!Use[i])
       {
           DFS(i);
           Nc++;
       }
   }
    printf("%d\n",Nc);
    return 0;
}