#include <cstdio>
#include <vector>
#define LIM 100023
using namespace std;
vector<int>adj[LIM];
int vis[LIM],n,m;
void dfs(int nod)
{
    vis[nod]=1;
    vector<int>::iterator it;
    for(it=adj[nod].begin();it!=adj[nod].end();++it)
    {
        if(vis[*it]==0) dfs(*it);
    }
}
int main()
{
    freopen ("dfs.in","r",stdin);
    freopen ("dfs.out","w",stdout);
    scanf("%d%d",&n,&m);
    int x,y;
    for(int i=1;i<=m;i++)
    {
        scanf("%d%d",&x,&y);
        adj[x].push_back(y);
        adj[y].push_back(x);
    }
    int ct=0;
    for(int i=1;i<=n;i++)
    {
        if(vis[i]==0)
        {
            ct++;
            dfs(i);
        }
    }
    printf("%d\n",ct);
}