#include<cstdio>
#include<cstdlib>
#include<vector>
#define NMAX 100000
using namespace std;
int sel[NMAX];
vector <int>v[NMAX];
void df(int i)
{
     sel[i]=1;
     for(int j=0;j<v[i].size();j++)
             if(sel[v[i][j]]==0)
             df(v[i][j]);
}
int main()
{
    freopen("dfs.in","r",stdin);
    freopen("dfs.out","w",stdout);
    int n,m,i,a,b;
    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);
    }
    a=0;
    for(i=1;i<=n;i++)
    {
                     if(sel[i]==0)
                     {
                                  df(i);
                                  a++;
                     }
    }
    printf("%d",a);
    return 0;
}