#include <fstream>
#include <vector>
#include <queue>
using namespace std ;
ifstream cin("dfs.in");
ofstream cout("dfs.out");
vector<int> g[100002];
int viz[100002],n,m,ans;
void dfs(int nod){
    viz[nod]=1;
    for(auto it : g[nod]){
        if(viz[it]==0)
            dfs(it);
    }
}
int main()
{
    cin>>n>>m;
    int x,y;
    for(int i=1;i<=m;i++){
        cin>>x>>y;
        g[x].push_back(y);
        g[y].push_back(x);
    }
    for(int i=1;i<=n;i++){
        if(viz[i]==0){
            ans++;
            dfs(i);
        }
    }
    cout<<ans;
    return 0 ;
}