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

int n,m;
int a[101][101];
int p[101][101];
const int inf = 10000000;
int viz[100001];

vector<int>L[100001];
vector<int>v;

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

void citire()
{
 fin>>n>>m;
 int i,j;
 for(i=1;i<=m;i++)
 {
     int x,y;
     fin>>x>>y;
    L[x].push_back(y);
    L[y].push_back(x);
 }
}

void df(int x)
{
    v.push_back(x);
    int i;
    viz[x]=1;
    for(i=0;i<L[x].size();i++)
    if(!viz[L[x][i]])
        df(L[x][i]);
}
int main()
{
    int nr_c=0;
    citire();
    for(int i=1;i<=n;i++)
        if(!viz[i])
        {
            df(i);
            nr_c++;
        }

    fout<<nr_c;
    return 0;
}