#include <iostream>
#include <fstream>
#include <vector>
#include <bitset>
#include <map>
//http://www.infoarena.ro/problema/dfs
using namespace std;
#define MAX 100020
ifstream in("dfs.in");
ofstream out("dfs.out");

vector <int> v[MAX];
int n,m,i,nr=0;
bitset <MAX> viz;
inline void dfs(int nod)
{  viz[nod]=1;
    for(vector < int > :: iterator it=v[nod].begin();it!=v[nod].end();++it)
        if(viz[*it]==0)dfs(*it);

}
int main()
{   int x,y;
     in>>n>>m;
    for(i=1;i<=m;i++)
    {
        in>>x>>y;
        v[x].push_back(y);
        v[y].push_back(x);
    }
    for(i=1;i<=n;i++)
    if(viz[i]==0){dfs(i); nr++;}
    out<<nr;
    return 0;
}