#include <iostream>
#include<vector>
#include<fstream>
using namespace std;
ifstream f("dfs.in");
ofstream g("dfs.out");

bool v[100001];
vector<int> Muchii[100001];
int n,m,X,i,x,y,insule;

void dfs(int n)
{
    v[n]=1;
    for(unsigned int i=0;i<Muchii[n].size();i++)
        if(!v[Muchii[n][i]])
            {
                //cout<<Muchii[n][i]<<" ";
                dfs(Muchii[n][i]);
            }
}

int main()
{
    cin>>n>>m;
    for(i=0;i<m;i++)
    {
        f>>x>>y;
        Muchii[x].push_back(y);
        Muchii[y].push_back(x);
    }

    for(unsigned int i=1;i<=n;i++)
    {
        if(!v[i])
        {
            insule++;
            dfs(i);
        }
    }
    g<<insule;
    return 0;
}