#include<iostream>
#include<algorithm>
#include<fstream>
#include<vector>
using namespace std;
#define Nmax 1000000
ifstream in("dfs.in");
ofstream out("dfs.out");
int n,nrc;
vector<bool> viz(Nmax,false);
vector <vector <int> >  v(Nmax);
void dfs(int x)
{
    viz[x]=true;
    for(int i=0;i<v[x].size();i++)
        if(!viz[v[x][i]])
          dfs(v[x][i]);
}
int main()
{
    int m,i,x,y;
    in>>n>>m;
    for(i=0;i<m;i++)
    {
        in>>x>>y;
        v[x].push_back(y);
        v[y].push_back(x);
    }
    for(int i=1;i<=n;i++)
        if(!viz[i])
    {
        nrc++;
        dfs(i);
    }
    out<<nrc;
}