#include <iostream>
#include <fstream>
#include <vector>
#include <algorithm>
using namespace std;

ifstream fin("dfs.in");
ofstream fout("dfs.out");

const int N=100001;
vector<int> a[N];
bool viz[N];
int n,m,y;

void dfs(int x)
{
    viz[x]=true;
    for(auto y:a[x])
    {
        if(!viz[y])
            dfs(y);
    }
}

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